Systems and methods for inducing negative pressure in a portion of a urinary tract of a patient

ABSTRACT

Ureteral or bladder catheters are provided, including (a) a proximal portion; and (b) a distal portion, the distal portion including a retention portion that includes one or more protected drainage holes, ports or perforations and is configured to establish an outer periphery or protective surface area that inhibits mucosal tissue from occluding the one or more protected drainage holes, ports or perforations upon application of negative pressure through the catheter. Systems, kits and methods for inducing negative pressure to increase renal function also are provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/205,987, filed Nov. 30, 2018, which is a continuation-in-part of U.S.patent application Ser. No. 15/879,770 filed Jan. 25, 2018, which is acontinuation-in-part of U.S. patent application Ser. No. 15/687,064filed Aug. 25, 2017, which is a continuation-in-part of U.S. patentapplication Ser. No. 15/411,884 filed Jan. 20, 2017, which is acontinuation-in-part of U.S. patent application Ser. No. 15/214,955filed Jul. 20, 2016, which claims the benefit of U.S. ProvisionalApplication No. 62/300,025 filed Feb. 25, 2016, U.S. ProvisionalApplication No. 62/278,721, filed Jan. 14, 2016, U.S. ProvisionalApplication No. 62/260,966 filed Nov. 30, 2015, and U.S. ProvisionalApplication No. 62/194,585, filed Jul. 20, 2015, each of which isincorporated by reference herein in their entireties.

Also, U.S. patent application Ser. No. 15/879,770 filed Jan. 25, 2018 isa continuation-in-part of U.S. patent application Ser. No. 15/687,083filed Aug. 25, 2017, which is a continuation-in-part of U.S. patentapplication Ser. No. 15/411,884 filed Jan. 20, 2017, which is acontinuation-in-part of U.S. patent application Ser. No. 15/214,955filed Jul. 20, 2016, which claims the benefit of U.S. ProvisionalApplication No. 62/300,025 filed Feb. 25, 2016, U.S. ProvisionalApplication No. 62/278,721, filed Jan. 14, 2016, U.S. ProvisionalApplication No. 62/260,966 filed Nov. 30, 2015, and U.S. ProvisionalApplication No. 62/194,585, filed Jul. 20, 2015, each of which isincorporated by reference herein in its entirety.

Also, U.S. patent application Ser. No. 15/879,770 filed Jan. 25, 2018 isa continuation-in-part of U.S. patent application Ser. No. 15/745,823filed Jan. 18, 2018, which is the U.S. national phase ofPCT/US2016/043101, filed Jul. 20, 2016, which claims the benefit of U.S.Provisional Application No. 62/300,025 filed Feb. 25, 2016, U.S.Provisional Application No. 62/278,721, filed Jan. 14, 2016, U.S.Provisional Application No. 62/260,966 filed Nov. 30, 2015, and U.S.Provisional Application No. 62/194,585, filed Jul. 20, 2015, each ofwhich is incorporated by reference herein in its entirety.

Also, U.S. patent application Ser. No. 15/879,770 filed Jan. 25, 2018claims the benefit of U.S. Provisional Application No. 62/489,789 filedApr. 25, 2017 and U.S. Provisional Application No. 62/489,831 filed Apr.25, 2017.

BACKGROUND Technical Field

The present disclosure relates to methods and devices for treatingimpaired renal function across a variety of disease states and, inparticular, to methods for removing fluid (e.g., urine) from a patientby using, for example, ureteral stent(s), ureteral catheter(s) and/or abladder catheter, or a combination of ureteral stent(s) and/or ureteralcatheter(s) and a bladder catheter, by applying negative pressurethrough the ureteral catheter(s), ureteral stent(s) and/or bladdercatheter.

Background

The renal or urinary system includes a pair of kidneys, each kidneybeing connected by a ureter to the bladder, and a urethra for drainingfluid or urine produced by the kidneys from the bladder. The kidneysperform several vital functions for the human body including, forexample, filtering the blood to eliminate waste in the form of urine.The kidneys also regulate electrolytes (e.g., sodium, potassium andcalcium) and metabolites, blood volume, blood pressure, blood pH, fluidvolume, production of red blood cells, and bone metabolism. Adequateunderstanding of the anatomy and physiology of the kidneys is useful forunderstanding the impact that altered hemodynamics and other fluidoverload conditions have on their function.

In normal anatomy, the two kidneys are located retroperitoneally in theabdominal cavity. The kidneys are bean-shaped encapsulated organs. Urineis formed by nephrons, the functional unit of the kidney, and then flowsthrough a system of converging tubules called collecting ducts. Thecollecting ducts join together to form minor calyces, then majorcalyces, which ultimately join near the concave portion of the kidney(renal pelvis). A major function of the renal pelvis is to direct urineflow to the ureter. Urine flows from the renal pelvis into the ureter, atube-like structure that carries the urine from the kidneys into thebladder. The outer layer of the kidney is called the cortex, and is arigid fibrous encapsulation. The interior of the kidney is called themedulla. The medulla structures are arranged in pyramids.

Each kidney is made up of approximately one million nephrons. Eachnephron includes the glomerulus, Bowman's capsule, and tubules. Thetubules include the proximal convoluted tubule, the loop of Henle, thedistal convoluted tubule, and the collecting duct. The nephronscontained in the cortex layer of the kidney are distinct from theanatomy of those contained in the medulla. The principal difference isthe length of the loop of Henle. Medullary nephrons contain a longerloop of Henle, which, under normal circumstances, allows greaterregulation of water and sodium reabsorption than in the cortex nephrons.

The glomerulus is the beginning of the nephron, and is responsible forthe initial filtration of blood. Afferent arterioles pass blood into theglomerular capillaries, where hydrostatic pressure pushes water andsolutes into Bowman's capsule. Net filtration pressure is expressed asthe hydrostatic pressure in the afferent arteriole minus the hydrostaticpressure in Bowman's space minus the osmotic pressure in the efferentarteriole.Net Filtration Pressure=Hydrostatic Pressure (AfferentArteriole)−Hydrostatic Pressure (Bowman's Space)−Osmotic Pressure(Efferent Arteriole)  (Equation 1)

The magnitude of this net filtration pressure defined by Equation 1determines how much ultra-filtrate is formed in Bowman's space anddelivered to the tubules. The remaining blood exits the glomerulus viathe efferent arteriole. Normal glomerular filtration, or delivery ofultra-filtrate into the tubules, is about 90 ml/min/1.73 m².

The glomerulus has a three-layer filtration structure, which includesthe vascular endothelium, a glomerular basement membrane, and podocytes.Normally, large proteins such as albumin and red blood cells, are notfiltered into Bowman's space. However, elevated glomerular pressures andmesangial expansion create surface area changes on the basement membraneand larger fenestrations between the podocytes allowing larger proteinsto pass into Bowman's space.

Ultra-filtrate collected in Bowman's space is delivered first to theproximal convoluted tubule. Re-absorption and secretion of water andsolutes in the tubules is performed by a mix of active transportchannels and passive pressure gradients. The proximal convoluted tubulesnormally reabsorb a majority of the sodium chloride and water, andnearly all glucose and amino acids that were filtered by the glomerulus.The loop of Henle has two components that are designed to concentratewastes in the urine. The descending limb is highly water permeable andreabsorbs most of the remaining water. The ascending limb reabsorbs 25%of the remaining sodium chloride, creating a concentrated urine, forexample, in terms of urea and creatinine. The distal convoluted tubulenormally reabsorbs a small proportion of sodium chloride, and theosmotic gradient creates conditions for the water to follow.

Under normal conditions, there is a net filtration of approximately 14mmHg. The impact of venous congestion can be a significant decrease innet filtration, down to approximately 4 mmHg. See Jessup M., Thecardiorenal syndrome: Do we need a change of strategy or a change oftactics?, JACC 53(7):597-600, 2009 (hereinafter “Jessup”). The secondfiltration stage occurs at the proximal tubules. Most of the secretionand absorption from urine occurs in tubules in the medullary nephrons.Active transport of sodium from the tubule into the interstitial spaceinitiates this process. However, the hydrostatic forces dominate the netexchange of solutes and water. Under normal circumstances, it isbelieved that 75% of the sodium is reabsorbed back into lymphatic orvenous circulation. However, because the kidney is encapsulated, it issensitive to changes in hydrostatic pressures from both venous andlymphatic congestion. During venous congestion the retention of sodiumand water can exceed 85%, further perpetuating the renal congestion. SeeVerbrugge et al., The kidney in congestive heart failure: Arenatriuresis, sodium, and diruetucs really the good, the bad and theugly? European Journal of Heart Failure 2014: 16, 133-42 (hereinafter“Verbrugge”).

Venous congestion can lead to a prerenal form of acute kidney injury(AKI). Prerenal AKI is due to a loss of perfusion (or loss of bloodflow) through the kidney. Many clinicians focus on the lack of flow intothe kidney due to shock. However, there is also evidence that a lack ofblood flow out of the organ due to venous congestion can be a clinicallyimportant sustaining injury. See Damman K, Importance of venouscongestion for worsening renal function in advanced decompensated heartfailure, JACC 17:589-96, 2009 (hereinafter “Damman”).

Prerenal AKI occurs across a wide variety of diagnoses requiringcritical care admissions. The most prominent admissions are for sepsisand Acute Decompensated Heart Failure (ADHF). Additional admissionsinclude cardiovascular surgery, general surgery, cirrhosis, trauma,burns, and pancreatitis. While there is wide clinical variability in thepresentation of these disease states, a common denominator is anelevated central venous pressure. In the case of ADHF, the elevatedcentral venous pressure caused by heart failure leads to pulmonaryedema, and, subsequently, dyspnea in turn precipitating the admission.In the case of sepsis, the elevated central venous pressure is largely aresult of aggressive fluid resuscitation. Whether the primary insult waslow perfusion due to hypovolemia or sodium and fluid retention, thesustaining injury is the venous congestion resulting in inadequateperfusion.

Hypertension is another widely recognized state that createsperturbations within the active and passive transport systems of thekidney(s). Hypertension directly impacts afferent arteriole pressure andresults in a proportional increase in net filtration pressure within theglomerulus. The increased filtration fraction also elevates theperitubular capillary pressure, which stimulates sodium and waterre-absorption. See Verbrugge.

Because the kidney is an encapsulated organ, it is sensitive to pressurechanges in the medullary pyramids. The elevated renal venous pressurecreates congestion that leads to a rise in the interstitial pressures.The elevated interstitial pressures exert forces upon both theglomerulus and tubules. See Verbrugge. In the glomerulus, the elevatedinterstitial pressures directly oppose filtration. The increasedpressures increase the interstitial fluid, thereby increasing thehydrostatic pressures in the interstitial fluid and peritubularcapillaries in the medulla of the kidney. In both instances, hypoxia canensue leading to cellular injury and further loss of perfusion. The netresult is a further exacerbation of the sodium and water re-absorptioncreating a negative feedback. See Verbrugge, 133-42. Fluid overload,particularly in the abdominal cavity is associated with many diseasesand conditions, including elevated intra-abdominal pressure, abdominalcompartment syndrome, and acute renal failure. Fluid overload can beaddressed through renal replacement therapy. See Peters, C. D., Shortand Long-Term Effects of the Angiotensin II Receptor BlockerIrbesartanon Intradialytic Central Hemodynamics: A RandomizedDouble-Blind Placebo-Controlled One-Year Intervention Trial (the SAFIRStudy), PLoS ONE (2015) 10(6): e0126882.doi:10.1371/journal.pone.0126882 (hereinafter “Peters”). However, such aclinical strategy provides no improvement in renal function for patientswith the cardiorenal syndrome. See Bart B, Ultrafiltration indecompensated heart failure with cardiorenal syndrome, NEJM 2012;367:2296-2304 (hereinafter “Bart”).

In view of such problematic effects of fluid retention, systems andmethods for improving removal of fluid such as urine from the patientand, specifically for increasing quantity and quality of fluid outputfrom the kidneys, are needed.

SUMMARY

In some examples, a ureteral or bladder catheter is provided, thecatheter comprising (a) a proximal portion; and (b) a distal portion,the distal portion comprising a retention portion that comprises one ormore protected drainage holes, ports or perforations and is configuredto establish an outer periphery or protective surface area that inhibitsmucosal tissue from occluding the one or more protected drainage holes,ports or perforations upon application of negative pressure through thecatheter.

In some examples, a system for inducing negative pressure in a portionof a urinary tract of a patient is provided, the system comprising: (a)a ureteral catheter comprising a distal portion for insertion within thepatient's kidney and a proximal portion; (b) a bladder cathetercomprising a distal portion for insertion within the patient's bladderand a proximal portion for application of negative pressure, theproximal portion extending outside of the patient's body; and (c) a pumpexternal to the patient's body for application of negative pressurethrough both the bladder catheter and the ureteral catheter, which inturn causes fluid from the kidney to be drawn into the ureteralcatheter, through both the ureteral catheter and the bladder catheter,and then outside the patient's body.

In some examples, a kit for inducing negative pressure in a portion of aurinary tract of a patient is provided, the kit comprising: one or twoureteral catheters, each ureteral catheter comprising (a) a proximalportion; and (b) a distal portion, the distal portion comprising aretention portion that comprises one or more protected drainage holes,ports or perforations and is configured to establish an outer peripheryor protective surface area that inhibits mucosal tissue from occludingthe one or more protected drainage holes, ports or perforations uponapplication of negative pressure through the catheter; and a pumpexternal to the patient's body for application of negative pressurethrough both the bladder catheter and the ureteral catheter, which inturn causes fluid from the kidney to be drawn into the ureteralcatheter, through both the ureteral catheter and the bladder catheter,and then outside the patient's body.

In some examples, a kit is provided, the kit comprising: a plurality ofdisposable bladder catheters, each bladder catheter comprising (a) aproximal portion; and (b) a distal portion, the distal portioncomprising a retention portion that comprises one or more protecteddrainage holes, ports or perforations and is configured to establish anouter periphery or protective surface area that inhibits mucosal tissuefrom occluding the one or more protected drainage holes, ports orperforations upon application of negative pressure through the catheter;instructions for deploying the bladder catheter; and instructions forconnecting the proximal end of the bladder catheter to a pump and foroperating the pump to draw urine through the drainage lumen of thebladder catheter.

In some examples, a method for inducing negative pressure in a portionof a urinary tract of a patient is provided, the method comprising:deploying a ureteral catheter into a ureter of a patient to maintainpatency of fluid flow between a kidney and a bladder of the patient, theureteral catheter comprising a distal portion for insertion within thepatient's kidney and a proximal portion; deploying a bladder catheterinto the bladder of the patient, wherein the bladder catheter comprisesa distal portion for insertion within the patient's bladder and aproximal portion for application of negative pressure, the proximalportion extending outside of the patient's body; and applying negativepressure to the proximal end of the bladder catheter to induce negativepressure in a portion of the urinary tract of the patient to removefluid from the patient.

Non-limiting examples, aspects or embodiments of the present inventionwill now be described in the following numbered clauses:

Clause 1. A ureteral catheter comprising (a) a proximal portion; and (b)a distal portion, the distal portion comprising a retention portion thatcomprises one or more protected drainage holes, ports or perforationsand is configured to establish an outer periphery or protective surfacearea that inhibits mucosal tissue from occluding the one or moreprotected drainage holes, ports or perforations upon application ofnegative pressure through the catheter.

Clause 2. The ureteral catheter according to Clause 1, wherein the oneor more protected drainage holes, ports or perforations are disposed ona protected surface area or inner surface area of the retention portion,and wherein, upon application of negative pressure, the mucosal tissueconforms or collapses onto the outer periphery or protective surfacearea of the retention portion of the catheter and is thereby preventedor inhibited from occluding the one or more of the protected drainageholes, ports or perforations.

Clause 3. The ureteral catheter according to any of Clauses 1 or 2,wherein the retention portion comprises one or more helical coils, eachcoil having an outwardly facing side and an inwardly facing side, andwherein the outer periphery or protective surface area comprises theoutwardly facing side(s) of the one or more helical coil(s), and the oneor more protected drainage holes, ports or perforations are disposed onthe inwardly facing side(s) of the one or more helical coil(s).

Clause 4. The ureteral catheter according to any of Clauses 1-3, whereinthe retention portion is configured into a funnel-shaped support havingan outer surface and an inner surface, and wherein the outer peripheryor protective surface area comprises the outer surface of thefunnel-shaped support, and the one or more drainage holes, ports orperforations are disposed on the inner surface of the funnel-shapedsupport.

Clause 5. The ureteral catheter according to any of Clauses 1-4, whereinthe retention portion is configured to be extended into a deployedposition in which a diameter of the retention portion is greater than adiameter of the drainage lumen portion.

Clause 6. A bladder catheter comprising (a) a proximal portion; and (b)a distal portion, the distal portion comprising a retention portion thatcomprises one or more protected drainage holes, ports or perforationsand is configured to establish an outer periphery or protective surfacearea that inhibits mucosal tissue from occluding the one or moreprotected drainage holes, ports or perforations upon application ofnegative pressure through the catheter.

Clause 7. The bladder catheter according to Clause 6, wherein the one ormore protected drainage holes, ports or perforations are disposed on aprotected surface area or inner surface area of the retention portion,and wherein, upon application of negative pressure, the mucosal tissueconforms or collapses onto the outer periphery or protective surfacearea of the retention portion of the catheter and is thereby preventedor inhibited from occluding the one or more of the protected drainageholes, ports or perforations.

Clause 8. The bladder catheter according to Clause 6 or 7, wherein theretention portion comprises one or more helical coils, each coil havingan outwardly facing side and an inwardly facing side, and wherein theouter periphery or protective surface area comprises the outwardlyfacing side(s) of the one or more helical coil(s), and the one or moreprotected drainage holes, ports or perforations are disposed on theinwardly facing side(s) of the one or more helical coil(s).

Clause 9. The bladder catheter according to any of Clauses 6-8, whereinthe retention portion is configured into a funnel-shaped support havingan outer surface and an inner surface, and wherein the outer peripheryor protective surface area comprises the outer surface of thefunnel-shaped support, and the one or more drainage holes, ports orperforations are disposed on the inner surface of the funnel-shapedsupport.

Clause 10. The bladder catheter according to any of Clauses 6-9, whereinthe retention portion is configured to be extended into a deployedposition in which a diameter of the retention portion is greater than adiameter of the drainage lumen portion.

Clause 11. A system for inducing negative pressure in a portion of aurinary tract of a patient, the system comprising: (a) a ureteralcatheter comprising a distal portion for insertion within the patient'skidney and a proximal portion; (b) a bladder catheter comprising adistal portion for insertion within the patient's bladder and a proximalportion for application of negative pressure, the proximal portionextending outside of the patient's body; and (c) a pump external to thepatient's body for application of negative pressure through both thebladder catheter and the ureteral catheter, which in turn causes fluidfrom the kidney to be drawn into the ureteral catheter, through both theureteral catheter and the bladder catheter, and then outside of thepatient's body.

Clause 12. The system according to Clause 11, wherein the proximalportion of the ureteral catheter is in fluid communication with thedistal portion of the bladder catheter.

Clause 13. The system according to Clause 11 or 12, wherein the distalportion of the ureteral catheter comprises a retention portion thatcomprises one or more protected drainage holes, ports or perforationsand is configured to establish an outer periphery or protective surfacearea that inhibits mucosal tissue from occluding the one or moreprotected drainage holes, ports or perforations upon the application ofnegative pressure by the pump.

Clause 14. The system according to any of Clauses 11-13, wherein the oneor more protected drainage holes, ports or perforations are disposed ona protected surface area or inner surface area of the retention portion,and wherein, upon application of negative pressure, the mucosal tissueconforms or collapses onto the outer periphery or protective surfacearea of the retention portion of the catheter and is thereby preventedor inhibited from occluding the one or more of the protected drainageholes, ports or perforations.

Clause 15. The system according to any of Clauses 11-15, wherein thedistal portion of the bladder catheter comprises a retention portionthat comprises one or more protected drainage holes, ports orperforations and is configured to establish an outer periphery orprotective surface area that inhibits mucosal tissue from occluding theone or more protected drainage holes, ports or perforations upon theapplication of negative pressure by the pump.

Clause 16. The system according to Clause 15, wherein the one or moreprotected drainage holes, ports or perforations are disposed on aprotected surface area or inner surface area of the retention portion,and wherein, upon application of negative pressure, the mucosal tissueconforms or collapses onto the outer periphery or protective surfacearea of the retention portion of the catheter and is thereby preventedor inhibited from occluding the one or more of the protected drainageholes, ports or perforations.

Clause 17. The system according to any of Clauses 11-16, furthercomprising one or more physiological sensors associated with thepatient, the physiological sensors being configured to provideinformation representative of at least one physical parameter to acontroller.

Clause 18. The system according to any of Clauses 11-17, wherein thepump provides a sensitivity of about 10 mmHg or less.

Clause 19. The system according to any of Clauses 11-18, wherein thenegative pressure is provided within a range of about 2 mm Hg to about150 mm Hg.

Clause 20. A system for inducing negative pressure in a portion of aurinary tract of a patient, the system comprising: (a) at least oneureteral catheter, the at least one ureteral catheter comprising adistal portion for insertion within the patient's kidney and a proximalportion; (b) a bladder catheter comprising a distal portion forinsertion within the patient's bladder and a proximal portion forreceiving negative pressure from a negative pressure source, wherein atleast one of the at least one ureteral catheter(s) or the bladdercatheter comprises (a) a proximal portion; and (b) a distal portion, thedistal portion comprising a retention portion that comprises one or moreprotected drainage holes, ports or perforations and is configured toestablish an outer periphery or protective surface area that inhibitsmucosal tissue from occluding the one or more protected drainage holes,ports or perforations upon application of negative pressure through thecatheter; and (c) a negative pressure source for application of negativepressure through both the bladder catheter and the ureteral catheter(s),which in turn causes fluid from the kidney to be drawn into the ureteralcatheter(s), through both the ureteral catheter(s) and the bladdercatheter, and then outside of the patient's body.

Clause 21. The system according to Clause 20, wherein the proximalportion of the at least one ureteral catheter(s) is in fluidcommunication with the distal portion of the bladder catheter.

Clause 22. The system according to any of Clauses 20 or 21, wherein thedistal portion of the at least one ureteral catheter(s) comprises aretention portion that comprises one or more protected drainage holes,ports or perforations and is configured to establish an outer peripheryor protective surface area that inhibits mucosal tissue from occludingthe one or more protected drainage holes, ports or perforations upon theapplication of negative pressure from the negative pressure source.

Clause 23. The system according to Clause 22, wherein the one or moreprotected drainage holes, ports or perforations are disposed on aprotected surface area or inner surface area of the retention portion,and wherein, upon application of negative pressure, the mucosal tissueconforms or collapses onto the outer periphery or protective surfacearea of the retention portion of the catheter and is thereby preventedor inhibited from occluding the one or more of the protected drainageholes, ports or perforations.

Clause 24. The system according to any of Clauses 20-23, wherein thedistal portion of the bladder catheter comprises a retention portionthat comprises one or more protected drainage holes, ports orperforations and is configured to establish an outer periphery orprotective surface area that inhibits mucosal tissue from occluding theone or more protected drainage holes, ports or perforations upon theapplication of negative pressure from the negative pressure source.

Clause 25. The system according to Clause 24, wherein the one or moreprotected drainage holes, ports or perforations are disposed on aprotected surface area or inner surface area of the retention portion,and wherein, upon application of negative pressure, the mucosal tissueconforms or collapses onto the outer periphery or protective surfacearea of the retention portion of the catheter and is thereby preventedor inhibited from occluding the one or more of the protected drainageholes, ports or perforations.

Clause 26. The system according to any of Clauses 20-25, furthercomprising one or more physiological sensors associated with thepatient, the physiological sensors being configured to provideinformation representative of at least one physical parameter to acontroller.

Clause 27. The system according to any of Clauses 20-25, wherein thenegative pressure source comprises a pump external to the patient's bodyfor application of negative pressure through both the bladder catheterand the ureteral catheter, which in turn causes fluid from the kidney tobe drawn into the ureteral catheter, through both the ureteral catheterand the bladder catheter, and then outside of the patient's body.

Clause 28. The system according to any of Clauses 20-25, wherein thenegative pressure source comprises a vacuum source external to thepatient's body for application and regulation of negative pressurethrough both the bladder catheter and the ureteral catheter, which inturn causes fluid from the kidney to be drawn into the ureteralcatheter, through both the ureteral catheter and the bladder catheter,and then outside of the patient's body.

Clause 29. The system according to Clause 28, wherein the vacuum sourceis selected from the group consisting of a wall suction source, vacuumbottle, and manual vacuum source.

Clause 30. The system according to Clause 28, wherein the vacuum sourceis provided by a pressure differential.

Clause 31. The system according to any of Clauses 20-30, wherein thenegative pressure received from the negative pressure source iscontrolled manually, automatically, or combinations thereof.

Clause 32. The system according to any of Clauses 20-31, wherein acontroller is used to regulate negative pressure from the negativepressure source.

Clause 33. The system according to Clause 27, wherein the pump providesa sensitivity of about 10 mmHg or less.

Clause 34. The system according to any of Clauses 20-33, wherein thenegative pressure is provided within a range of about 2 mm Hg to about150 mmHg.

Clause 35. A system for inducing negative pressure in a portion of aurinary tract of a patient, the system comprising: (a) at least oneureteral catheter, the at least one ureteral catheter comprising adistal portion for insertion within the patient's kidney and a proximalportion; (b) a bladder catheter comprising a distal portion forinsertion within the patient's bladder and a proximal portion forreceiving a pressure differential, wherein the pressure differentialcauses fluid from the kidney to be drawn into the ureteral catheter(s),through both the ureteral catheter(s) and the bladder catheter, and thenoutside of the patient's body, the pressure differential being appliedto increase, decrease and/or maintain fluid flow therethrough, whereinat least one of the at least one ureteral catheter(s) or the bladdercatheter comprises (a) a proximal portion; and (b) a distal portion, thedistal portion comprising a retention portion that comprises one or moreprotected drainage holes, ports or perforations and is configured toestablish an outer periphery or protective surface area that inhibitsmucosal tissue from occluding the one or more protected drainage holes,ports or perforations upon application of differential pressure throughthe catheter.

Clause 36. The system according to Clause 35, wherein the proximalportion of the at least one ureteral catheter(s) is in fluidcommunication with the distal portion of the bladder catheter.

Clause 37. The system according to any of Clauses 35 or 36, wherein thedistal portion of the at least one ureteral catheter(s) comprises aretention portion that comprises one or more protected drainage holes,ports or perforations and is configured to establish an outer peripheryor protective surface area that inhibits mucosal tissue from occludingthe one or more protected drainage holes, ports or perforations upon theapplication of the pressure differential.

Clause 38. The system according to Clause 37, wherein the one or moreprotected drainage holes, ports or perforations are disposed on aprotected surface area or inner surface area of the retention portion,and wherein, upon application of the pressure differential, the mucosaltissue conforms or collapses onto the outer periphery or protectivesurface area of the retention portion of the catheter and is therebyprevented or inhibited from occluding the one or more of the protecteddrainage holes, ports or perforations.

Clause 39. The system according to any of Clauses 35-38, wherein thedistal portion of the bladder catheter comprises a retention portionthat comprises one or more protected drainage holes, ports orperforations and is configured to establish an outer periphery orprotective surface area that inhibits mucosal tissue from occluding theone or more protected drainage holes, ports or perforations upon theapplication of the pressure differential.

Clause 40. The system according to Clause 39, wherein the one or moreprotected drainage holes, ports or perforations are disposed on aprotected surface area or inner surface area of the retention portion,and wherein, upon application of the pressure differential, the mucosaltissue conforms or collapses onto the outer periphery or protectivesurface area of the retention portion of the catheter and is therebyprevented or inhibited from occluding the one or more of the protecteddrainage holes, ports or perforations.

Clause 41. The system according to any of Clauses 35-40, furthercomprising one or more physiological sensors associated with thepatient, the physiological sensors being configured to provideinformation representative of at least one physical parameter to acontroller.

Clause 42. A kit for inducing negative pressure in a portion of aurinary tract of a patient, the kit comprising: one or two ureteralcatheters, each ureteral catheter comprising (a) a proximal portion; and(b) a distal portion, the distal portion comprising a retention portionthat comprises one or more protected drainage holes, ports orperforations and is configured to establish an outer periphery orprotective surface area that inhibits mucosal tissue from occluding theone or more protected drainage holes, ports or perforations uponapplication of negative pressure through the catheter; and a pumpexternal to the patient's body for application of negative pressurethrough both the bladder catheter and the ureteral catheter, which inturn causes fluid from the kidney to be drawn into the ureteralcatheter, through both the ureteral catheter and the bladder catheter,and then outside the patient's body.

Clause 43. The kit according to clause 42, further comprising a bladdercatheter.

Clause 44. The kit according to any of clauses 42 or 43, furthercomprising instructions for inserting a bladder catheter, and operatingthe pump to draw urine through a drainage lumen of a catheter deployedthe patient's bladder.

Clause 45. A kit comprising: a plurality of disposable bladdercatheters, each bladder catheter comprising (a) a proximal portion; and(b) a distal portion, the distal portion comprising a retention portionthat comprises one or more protected drainage holes, ports orperforations and is configured to establish an outer periphery orprotective surface area that inhibits mucosal tissue from occluding theone or more protected drainage holes, ports or perforations uponapplication of negative pressure through the catheter; instructions fordeploying the bladder catheter; and instructions for connecting theproximal end of the bladder catheter to a pump and for operating thepump to draw urine through the drainage lumen of the bladder catheter.

Clause 46. A method for inducing negative pressure in a portion of aurinary tract of a patient, the method comprising: deploying a ureteralcatheter into a ureter of a patient to maintain patency of fluid flowbetween a kidney and a bladder of the patient, the ureteral cathetercomprising a distal portion for insertion within the patient's kidneyand a proximal portion; deploying a bladder catheter into the bladder ofthe patient, wherein the bladder catheter comprises a distal portion forinsertion within the patient's bladder and a proximal portion forapplication of negative pressure, the proximal portion extending outsideof the patient's body; and applying negative pressure to the proximalend of the bladder catheter to induce negative pressure in a portion ofthe urinary tract of the patient to remove fluid from the patient.

Clause 47. The method according to clause 46, wherein at least one ofthe ureteral catheter or the bladder catheter comprises (a) a proximalportion; and (b) a distal portion, the distal portion comprising aretention portion that comprises one or more protected drainage holes,ports or perforations and is configured to establish an outer peripheryor protective surface area that inhibits mucosal tissue from occludingthe one or more protected drainage holes, ports or perforations uponapplication of negative pressure through the catheter.

Clause 48. The method according to clause 46 or 47, wherein the ureteralcatheter is deployed and remains in the patient's body for at least 24hours.

Clause 49. The method according to any of clauses 46-48, wherein theureteral catheter is deployed and remains in the patient's body for atleast 30 days or longer.

Clause 50. The method according to any of clauses 46-49, wherein thebladder catheter is replaced more often that the ureteral catheter.

Clause 51. The method according to any of clauses 46-50, whereinmultiple bladder catheters are placed and removed during the indwelltime for a single set of ureteral catheters.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and characteristics of the present disclosure,as well as the methods of operation and functions of the relatedelements of structures and the combination of parts and economies ofmanufacture, will become more apparent upon consideration of thefollowing description and the appended clauses with reference to theaccompanying drawings, all of which form a part of this specification,wherein like reference numerals designate corresponding parts in thevarious figures. It is to be expressly understood, however, that thedrawings are for the purpose of illustration and description only andare not intended as a definition of the limit of the invention.

Further features and other examples and advantages will become apparentfrom the following detailed description made with reference to thedrawings in which:

FIG. 1A is a schematic drawing of an indwelling portion of a systemcomprising a ureteral stent and a bladder catheter deployed in a urinarytract of a patient, according to an example of the present invention;

FIG. 1B is a schematic drawing of an indwelling portion of a systemcomprising a ureteral catheter and a bladder catheter deployed in aurinary tract of a patient, according to an example of the presentinvention;

FIG. 1C is a schematic drawing of an indwelling portion of a systemcomprising a ureteral catheter and a bladder catheter deployed in aurinary tract of a patient, according to an example of the presentinvention;

FIG. 1D is a perspective view of a retention portion of a bladdercatheter, according to an example of the present invention;

FIG. 1E is a cross sectional view of the retention portion of FIG. 1D,taken along line 1E-1E of FIG. 1D, according to an example of thepresent invention;

FIG. 1F is a schematic drawing of an indwelling portion of a systemcomprising a ureteral catheter and a bladder catheter deployed in aurinary tract of a patient, according to an example of the presentinvention;

FIG. 1G is a perspective view of a retention portion of a bladdercatheter, according to an example of the present invention;

FIG. 1H is a side elevational view of the retention portion of FIG. 1G,according to an example of the present invention;

FIG. 1I is a top plan view of the retention portion of FIG. 1G,according to an example of the present invention;

FIG. 1J is a perspective view of a retention portion of a bladdercatheter, according to an example of the present invention;

FIG. 1K is a perspective view of a retention portion of a bladdercatheter, according to an example of the present invention;

FIG. 1L is a side elevational view of a retention portion of a bladdercatheter prior to deployment, according to an example of the presentinvention;

FIG. 1M is a side elevational view of the retention portion of FIG. 1Lafter deployment, according to an example of the present invention;

FIG. 1N is a perspective view of a retention portion of a bladdercatheter, according to an example of the present invention;

FIG. 1O is a cross-sectional view of a portion of the retention portionof FIG. 1N, according to an example of the present invention;

FIG. 1P is a schematic drawing of an indwelling portion of a systemcomprising a ureteral catheter and a bladder catheter deployed in aurinary tract of a patient, according to an example of the presentinvention;

FIG. 1Q is a perspective view of a retention portion of a bladdercatheter, according to an example of the present invention;

FIG. 1R is a cross-sectional view of a portion of the retention portionof FIG. 1Q, according to an example of the present invention;

FIG. 1S is a perspective view of a retention portion of a bladdercatheter, according to an example of the present invention;

FIG. 1T is a cross-sectional view of a portion of the retention portionof FIG. 1S, according to an example of the present invention;

FIG. 1U is a schematic drawing of an indwelling portion of a systemcomprising a ureteral catheter and a bladder catheter deployed in aurinary tract of a patient, according to an example of the presentinvention;

FIG. 1V is a perspective view of a retention portion of a bladdercatheter, according to an example of the present invention;

FIG. 1W is a cross sectional view of the retention portion of FIG. 1V,taken along line 1W-1W of FIG. 1V, according to an example of thepresent invention;

FIG. 2A is a schematic drawing of an indwelling portion of a systemcomprising a ureteral catheter deployed in a urinary tract of a patient,according to an example of the present invention;

FIG. 2B is a schematic drawing of an indwelling portion of a systemcomprising a ureteral catheter deployed in a urinary tract of a patient,according to an example of the present invention;

FIG. 3 is a dimetric view of an example of a prior art transformableureteral stent according to FIG. 1 of PCT Patent Application PublicationWO 2017/019974, wherein the image on the left represents theuncompressed state of the stent and the image on the right representsthe compressed state of the stent;

FIG. 4 is a perspective view of an example of a prior art ureteral stentaccording to FIG. 4 of US Patent Application Publication No.2002/0183853 A1;

FIG. 5 is a perspective view of an example of a prior art ureteral stentaccording to FIG. 5 of US Patent Application Publication No.2002/0183853 A1;

FIG. 6 is a perspective view of an example of a prior art ureteral stentaccording to FIG. 7 of US Patent Application Publication No.2002/0183853 A1;

FIG. 7A is a schematic drawing of another example of an indwellingportion of a system comprising a ureteral catheter and a bladdercatheter deployed in a urinary tract of a patient, according to anexample of the present invention;

FIG. 7B is a schematic drawing of a system for inducing negativepressure to the urinary tract of a patient according to an example ofthe present invention;

FIG. 7C is a an enlarged schematic drawing of a portion of a ureteralcatheter according to the present invention positioned in the renalpelvis region of the kidney showing in phantom general changes believedto occur in the renal pelvis tissue in response to application ofnegative pressure through the ureteral catheter;

FIG. 8A is a perspective view of an exemplary catheter according to anexample of the present invention;

FIG. 8B is a front view of the catheter of FIG. 8A;

FIG. 9A is a schematic drawing of an example of a retention portion fora catheter according to an example of the present invention;

FIG. 9B is a schematic drawing of another example of a retention portionfor a catheter according to an example of the present invention;

FIG. 9C is a schematic drawing of another example of a retention portionfor a catheter according to an example of the present invention;

FIG. 9D is a schematic drawing of another example of a retention portionfor a catheter according to an example of the present invention;

FIG. 9E is a schematic drawing of another example of a retention portionfor a catheter according to an example of the present invention;

FIG. 10 is a front view of another example of a catheter according to anexample of the present invention;

FIG. 10A is a perspective view of the retention portion of the catheterof FIG. 10 enclosed by circle 10A according to an example of the presentinvention;

FIG. 10B is a front view of the retention portion of FIG. 10A accordingto an example of the present invention;

FIG. 10C is a rear view of the retention portion of FIG. 10A accordingto an example of the present invention;

FIG. 10D is a top view of the retention portion of FIG. 10A according toan example of the present invention;

FIG. 10E is a cross sectional view of the retention portion of FIG. 10Ataken along line 10E-10E according to an example of the presentinvention;

FIG. 10F is s a cross sectional view of the retention portion of FIG.10A taken along line 10E-10E according to an example of the presentinvention positioned in the renal pelvis region of the kidney showing ingeneral changes believed to occur in the renal pelvis tissue in responseto application of negative pressure through the ureteral catheter;

FIG. 10G is s a cross sectional view of the retention portion of FIG.10A taken along line 10E-10E according to an example of the presentinvention positioned in the bladder showing in general changes believedto occur in the bladder tissue in response to application of negativepressure through the bladder catheter;

FIG. 11 is a schematic drawing of a retention portion of a catheter in aconstrained or linear position according to an example of the presentinvention;

FIG. 12 is a schematic drawing of another example of a retention portionof a catheter in a constrained or linear position according to anexample of the present invention;

FIG. 13 is a schematic drawing of another example of a retention portionof a ureteral catheter in a constrained or linear position according toan example of the present invention;

FIG. 14 is a schematic drawing of another example of a retention portionof a catheter in a constrained or linear position according to anexample of the present invention;

FIG. 15A is a graph showing a percentage of fluid flow through openingsof an exemplary catheter as a function of position according to anexample of the present invention;

FIG. 15B is a graph showing a percentage of fluid flow through openingsof another exemplary catheter as a function of position according to anexample of the present invention;

FIG. 15C is a graph showing a percentage of fluid flow through openingsof another exemplary catheter as a function of position according to anexample of the present invention;

FIG. 16 is a schematic drawing of a retention portion of a cathetershowing stations for calculating fluid flow coefficients for a masstransfer balance evaluation according to an example of the presentinvention;

FIG. 17 is a schematic drawing of an indwelling portion of a systemcomprising a ureteral catheter and a bladder catheter deployed in aurinary tract of a patient, according to another example of the presentinvention;

FIG. 18A is side elevational view of a retention portion of a catheteraccording to an example of the present invention;

FIG. 18B is cross-sectional view of the retention portion of thecatheter of FIG. 18A taken along lines B-B of FIG. 18A;

FIG. 18C is a top plan view of the retention portion of the catheter ofFIG. 18A taken along lines C-C of FIG. 18A;

FIG. 18D is cross sectional view of a retention portion of a ureteralcatheter according to an example of the present invention positioned inthe renal pelvis region of the kidney showing in general changesbelieved to occur in the renal pelvis tissue in response to applicationof negative pressure through the ureteral catheter;

FIG. 18E is cross sectional view of a retention portion of a bladdercatheter according to an example of the present invention positioned inthe bladder showing in general changes believed to occur in the bladdertissue in response to application of negative pressure through thebladder catheter;

FIG. 19 is a side elevational view of a retention portion of anothercatheter according to an example of the present invention;

FIG. 20 is a side elevational view of a retention portion of anothercatheter according to an example of the present invention;

FIG. 21 is a side elevational view of a retention portion of anothercatheter according to an example of the present invention;

FIG. 22A is a perspective view of a retention portion of anotherureteral catheter according to an example of the present invention;

FIG. 22B is a top plan view of the retention portion of the catheter ofFIG. 22A taken along lines 22B-22B of FIG. 22A;

FIG. 23A is a perspective view of a retention portion of anothercatheter according to an example of the present invention;

FIG. 23B is a top plan view of the retention portion of the catheter ofFIG. 23A taken along lines 23B-23B of FIG. 23A;

FIG. 24A is a perspective view of a retention portion of anothercatheter according to an example of the present invention;

FIG. 24B is a cross sectional view of a retention portion of a ureteralcatheter according to an example of the present invention positioned inthe renal pelvis region of the kidney showing in general changesbelieved to occur in the renal pelvis tissue in response to applicationof negative pressure through the ureteral catheter;

FIG. 24C is a cross sectional view of a retention portion of a bladdercatheter according to an example of the present invention positioned inthe bladder showing in general changes believed to occur in the bladdertissue in response to application of negative pressure through thebladder catheter;

FIG. 25 is a side elevational view of a retention portion of anothercatheter according to an example of the present invention;

FIG. 26 is a side elevational view of a retention portion of anothercatheter according to an example of the present invention;

FIG. 27 is a cross-sectional side view of a retention portion of anothercatheter according to an example of the present invention;

FIG. 28A is a perspective view of a retention portion of anothercatheter according to an example of the present invention;

FIG. 28B is a top plan view of the retention portion of the catheter ofFIG. 28A;

FIG. 29A is a perspective view of a retention portion of anothercatheter according to an example of the present invention;

FIG. 29B is a top plan view of the retention portion of the catheter ofFIG. 29A;

FIG. 29C is a cross sectional view of a retention portion of a ureteralcatheter according to an example of the present invention positioned inthe renal pelvis region of the kidney showing in general changesbelieved to occur in the renal pelvis tissue in response to applicationof negative pressure through the ureteral catheter;

FIG. 30 is a perspective view of a retention portion of another catheteraccording to an example of the present invention;

FIG. 31 is a top plan view of the retention portion of the catheter ofFIG. 30;

FIG. 32A is a perspective view of a retention portion of anothercatheter according to an example of the present invention;

FIG. 32B is a top plan view of the retention portion of the catheter ofFIG. 32A;

FIG. 33 is a cross-sectional side elevational view of a retentionportion of another catheter according to an example of the presentinvention;

FIG. 34 is a cross-sectional side elevational view of a retentionportion of another catheter according to an example of the presentinvention;

FIG. 35A is a perspective view of a retention portion of anothercatheter according to an example of the present invention;

FIG. 35B is a cross-sectional side elevational view of the retentionportion of the catheter of FIG. 35A taken along lines B-B of FIG. 35A;

FIG. 36 is a side elevational view showing a cut away cross-sectionalview of the sheath surrounding a catheter according to an example of thepresent invention in a contracted configuration for insertion into apatient's ureter;

FIG. 37A is a schematic drawing of another example of a retentionportion for a catheter according to an example of the present invention;

FIG. 37B is a schematic drawing of a cross-sectional view of a portionof the retention portion of FIG. 37A, taken along lines B-B of FIG. 37A;

FIG. 38A is a schematic drawing of another example of a retentionportion for a catheter according to an example of the present invention;

FIG. 38B is a schematic drawing of a portion of a cross-sectional viewof the retention portion of FIG. 5A, taken along lines B-B of FIG. 38A;

FIG. 39A is a schematic drawing of another example of a retentionportion for a catheter according to an example of the present invention;

FIG. 39B is a schematic drawing of a cross section of another example ofa retention portion for a ureteral catheter according to an example ofthe present invention positioned in the renal pelvis region of thekidney showing in general changes believed to occur in the renal pelvistissue in response to application of negative pressure through theureteral catheter;

FIG. 39C is a schematic drawing of a cross section of another example ofa retention portion for a bladder catheter according to an example ofthe present invention positioned in the bladder showing in generalchanges believed to occur in the bladder tissue in response toapplication of negative pressure through the bladder catheter;

FIG. 40A is a schematic drawing of a cross section of another example ofa retention portion for a catheter according to an example of thepresent invention;

FIG. 40B is a schematic drawing of a cross section of another example ofa retention portion for a ureteral catheter according to an example ofthe present invention positioned in the renal pelvis region of thekidney showing in general changes believed to occur in the renal pelvistissue in response to application of negative pressure through theureteral catheter;

FIG. 40C is a schematic drawing of a cross section of another example ofa retention portion for a bladder catheter according to an example ofthe present invention positioned in the bladder showing in generalchanges believed to occur in the bladder tissue in response toapplication of negative pressure through the bladder catheter;

FIG. 41A is a schematic drawing of another example of a retentionportion for a catheter according to an example of the present invention;

FIG. 41B is a schematic drawing of a cross section of another example ofa retention portion for a ureteral catheter according to an example ofthe present invention positioned in the renal pelvis region of thekidney showing in general changes believed to occur in the renal pelvistissue in response to application of negative pressure through theureteral catheter;

FIG. 41C is a schematic drawing of a cross section of another example ofa retention portion for a bladder catheter according to an example ofthe present invention positioned in the bladder showing in generalchanges believed to occur in the bladder tissue in response toapplication of negative pressure through the bladder catheter;

FIG. 42A is a flow chart illustrating a process for insertion anddeployment of a system according to an example of the present invention;

FIG. 42B is a flow chart illustrating a process for applying negativepressure using a system according to an example of the presentinvention;

FIG. 43 is a schematic drawing of a nephron and surrounding vasculatureshowing a position of the capillary bed and convoluted tubules;

FIG. 44 is a schematic drawing of a system for inducing negativepressure to the urinary tract of a patient according to an example ofthe present invention;

FIG. 45A is a plan view of a pump for use with the system of FIG. 44according to an example of the present invention;

FIG. 45B is a side elevation view of the pump of FIG. 45A;

FIG. 46 is a schematic drawing of an experimental set-up for evaluatingnegative pressure therapy in a swine model according to the presentinvention;

FIG. 47 is a graph of creatinine clearance rates for tests conductedusing the experimental set-up shown in FIG. 21;

FIG. 48A is a low magnification photomicrograph of kidney tissue from acongested kidney treated with negative pressure therapy;

FIG. 48B is a high magnification photomicrograph of the kidney tissueshown in FIG. 48A;

FIG. 48C is a low magnification photomicrograph of kidney tissue from acongested and untreated (e.g., control) kidney;

FIG. 48D is a high magnification photomicrograph of the kidney tissueshown in FIG. 23C

FIG. 49 is a flow chart illustrating a process for reducing creatinineand/or protein levels of a patient according to an example of thepresent invention;

FIG. 50 is a flow chart illustrating a process for treating a patientundergoing fluid resuscitation according to an example of the presentinvention; and

FIG. 51 is a graph of serum albumin relative to baseline for testsconduct on swine using the experimental method described herein.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the singular form of “a”, “an”, and “the” include pluralreferents unless the context clearly states otherwise.

As used herein, the terms “right”, “left”, “top”, and derivativesthereof shall relate to the invention as it is oriented in the drawingfigures. The term “proximal” refers to the portion of the catheterdevice that is manipulated or contacted by a user and/or to a portion ofan indwelling catheter nearest to the urinary tract access site. Theterm “distal” refers to the opposite end of the catheter device that isconfigured to be inserted into a patient and/or to the portion of thedevice that is inserted farthest into the patient's urinary tract.However, it is to be understood that the invention can assume variousalternative orientations and, accordingly, such terms are not to beconsidered as limiting. Also, it is to be understood that the inventioncan assume various alternative variations and stage sequences, exceptwhere expressly specified to the contrary. It is also to be understoodthat the specific devices and processes illustrated in the attacheddrawings, and described in the following specification, are examples.Hence, specific dimensions and other physical characteristics related tothe embodiments disclosed herein are not to be considered as limiting.

For the purposes of this specification, unless otherwise indicated, allnumbers expressing quantities of ingredients, reaction conditions,dimensions, physical characteristics, and so forth used in thespecification and claims are to be understood as being modified in allinstances by the term “about.” Unless indicated to the contrary, thenumerical parameters set forth in the following specification andattached claims are approximations that can vary depending upon thedesired properties sought to be obtained by the present invention.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard deviation found in theirrespective testing measurements.

Also, it should be understood that any numerical range recited herein isintended to include all sub-ranges subsumed therein. For example, arange of “1 to 10” is intended to include any and all sub-ranges betweenand including the recited minimum value of 1 and the recited maximumvalue of 10, that is, all subranges beginning with a minimum value equalto or greater than 1 and ending with a maximum value equal to or lessthan 10, and all subranges in between, e.g., 1 to 6.3, or 5.5 to 10, or2.7 to 6.1.

As used herein, the terms “communication” and “communicate” refer to thereceipt or transfer of one or more signals, messages, commands, or othertype of data. For one unit or component to be in communication withanother unit or component means that the one unit or component is ableto directly or indirectly receive data from and/or transmit data to theother unit or component. This can refer to a direct or indirectconnection that can be wired and/or wireless in nature. Additionally,two units or components can be in communication with each other eventhough the data transmitted can be modified, processed, routed, and thelike, between the first and second unit or component. For example, afirst unit can be in communication with a second unit even though thefirst unit passively receives data, and does not actively transmit datato the second unit. As another example, a first unit can be incommunication with a second unit if an intermediary unit processes datafrom one unit and transmits processed data to the second unit. It willbe appreciated that numerous other arrangements are possible.

As used herein, “maintain patency of fluid flow between a kidney and abladder of the patient” means establishing, increasing or maintainingflow of fluid, such as urine, from the kidneys through the ureter(s),ureteral stent(s) and/or ureteral catheter(s) to the bladder and outsideof the body. In some examples, the fluid flow is facilitated ormaintained by providing a protective surface area 1001 in the upperurinary tract and/or bladder to prevent the uroendothelium fromcontracting or collapsing into the fluid column or stream. As usedherein, “fluid” means urine and any other fluid from the urinary tract.

As used herein, “negative pressure” means that the pressure applied tothe proximal end of the bladder catheter or the proximal end of theureteral catheter, respectively, is below the existing pressure at theproximal end of the bladder catheter or the proximal end of the ureteralcatheter, respectively, prior to application of the negative pressure,e.g., there is a pressure differential between the proximal end of thebladder catheter or the proximal end of the ureteral catheter,respectively, and the existing pressure at the proximal end of thebladder catheter or the proximal end of the ureteral catheter,respectively, prior to application of the negative pressure. Thispressure differential causes fluid from the kidney to be drawn into theureteral catheter or bladder catheter, respectively, or through both theureteral catheter and the bladder catheter, and then outside of thepatient's body. For example, negative pressure applied to the proximalend of the bladder catheter or the proximal end of the ureteral cathetercan be less than atmospheric pressure (less than about 760 mm Hg orabout 1 atm), or less than the pressure measured at the proximal end ofthe bladder catheter or the proximal end of the ureteral catheter priorto the application of negative pressure, such that fluid is drawn fromthe kidney and/or bladder. In some examples, the negative pressureapplied to the proximal end of the bladder catheter or the proximal endof the ureteral catheter can range from about 0.1 mmHg to about 150 mmHg, or about 0.1 mm Hg to about 50 mm Hg, or about 0.1 mm Hg to about 10mm Hg, or about 5 mm Hg to about 20 mm Hg, or about 45 mm Hg (gaugepressure at the pump 710 or at a gauge at the negative pressure source).In some examples, the negative pressure source comprises a pump externalto the patient's body for application of negative pressure through boththe bladder catheter and the ureteral catheter, which in turn causesfluid from the kidney to be drawn into the ureteral catheter, throughboth the ureteral catheter and the bladder catheter, and then outside ofthe patient's body. In some examples, the negative pressure sourcecomprises a vacuum source external to the patient's body for applicationand regulation of negative pressure through both the bladder catheterand the ureteral catheter, which in turn causes fluid from the kidney tobe drawn into the ureteral catheter, through both the ureteral catheterand the bladder catheter, and then outside of the patient's body. Insome examples, the vacuum source is selected from the group consistingof a wall suction source, vacuum bottle, and manual vacuum source, orthe vacuum source is provided by a pressure differential. In someexamples, the negative pressure received from the negative pressuresource can be controlled manually, automatically, or combinationsthereof. In some examples, a controller is used to regulate negativepressure from the negative pressure source. Non-limiting examples ofnegative and positive pressure sources are discussed in detail below.

As used herein, “positive pressure” means that the pressure applied tothe proximal end of the bladder catheter or the proximal end of theureteral catheter, respectively, is above the existing pressure at theproximal end of the bladder catheter or the proximal end of the ureteralcatheter, respectively, prior to application of the negative pressure,and causes fluid present in the ureteral catheter or bladder catheter,respectively, or through both the ureteral catheter and the bladdercatheter, to flow back towards the bladder or kidney. In some examples,the positive pressure applied to the proximal end of the bladdercatheter or the proximal end of the ureteral catheter can range fromabout 0.1 mmHg to about 150 mm Hg, or about 0.1 mm Hg to about 50 mm Hg,or about 0.1 mm Hg to about 10 mm Hg, or about 5 mm Hg to about 20 mmHg, or about 45 mm Hg (gauge pressure at the pump 710 or at a gauge atthe positive pressure source). The positive pressure source can beprovided by a pump or wall pressure source, or pressurized bottle, forexample, and can be controlled manually, automatically, or combinationsthereof. In some examples, a controller is used to regulate positivepressure from the positive pressure source.

Fluid retention and venous congestion are central problems in theprogression to advanced renal disease. Excess sodium ingestion coupledwith relative decreases in excretion leads to isotonic volume expansionand secondary compartment involvement. In some examples, the presentinvention is generally directed to devices and methods for facilitatingdrainage of urine or waste from the bladder, ureter, and/or kidney(s) ofa patient. In some examples, the present invention is generally directedto systems and methods for inducing a negative pressure in at least aportion of the bladder, ureter, and/or kidney(s), e.g., urinary system,of a patient. While not intending to be bound by any theory, it isbelieved that applying a negative pressure to at least a portion of thebladder, ureter, and/or kidney(s), e.g., urinary system, can offset themedullary nephron tubule re-absorption of sodium and water in somesituations. Offsetting re-absorption of sodium and water can increaseurine production, decrease total body sodium, and improve erythrocyteproduction. Since the intra-medullary pressures are driven by sodiumand, therefore, volume overload, the targeted removal of excess sodiumenables maintenance of volume loss. Removal of volume restores medullaryhemostasis. Normal urine production is 1.48-1.96 L/day (or 1-1.4ml/min).

Fluid retention and venous congestion are also central problems in theprogression of prerenal Acute Kidney Injury (AKI). Specifically, AKI canbe related to loss of perfusion or blood flow through the kidney(s).Accordingly, in some examples, the present invention facilitatesimproved renal hemodynamics and increases urine output for the purposeof relieving or reducing venous congestion. Further, it is anticipatedthat treatment and/or inhibition of AKI positively impacts and/orreduces the occurrence of other conditions, for example, reduction orinhibition of worsening renal function in patients with NYHA Class IIIand/or Class IV heart failure. Classification of different levels ofheart failure are described in The Criteria Committee of the New YorkHeart Association, (1994), Nomenclature and Criteria for Diagnosis ofDiseases of the Heart and Great Vessels, (9th ed.), Boston: Little,Brown & Co. pp. 253-256, the disclosure of which is incorporated byreference herein in its entirety. Reduction or inhibition of episodes ofAKI and/or chronically decreased perfusion may also be a treatment forStage 4 and/or Stage 5 chronic kidney disease. Chronic kidney diseaseprogression is described in National Kidney Foundation, K/DOQI ClinicalPractice Guidelines for Chronic Kidney Disease: Evaluation,Classification and Stratification. Am. J. Kidney Dis. 39:S1-S266, 2002(Suppl. 1), the disclosure of which is incorporated by reference hereinin its entirety.

Also, the ureteral catheters, ureteral stents and/or bladder cathetersdisclosed herein can be useful for preventing, delaying the onset of,and/or treating end-stage renal disease (“ESRD”). The average dialysispatient consumes about $90,000 per year in healthcare utilization for atotal cost to the US government of $33.9 Billion. Today, ESRD patientscomprise only 2.9% of Medicare's total beneficiaries, yet they accountover 13% of total spending. While the incidence and costs per patienthave stabilized in recent years, the volume of active patients continuesto rise.

The five stages of advanced chronic kidney disease (“CKD”) are basedupon glomerular filtration rate (GFR). Stage 1 (GFR>90) patients havenormal filtration, while stage 5 (GFR<15) have kidney failure. Like manychronic diseases, the diagnosis capture improves with increasing symptomand disease severity.

The CKD 3b/4 subgroup is a smaller subgroup that reflects importantchanges in disease progression, healthcare system engagement andtransition to ESRD. Presentation to the emergency department rises withseverity of CKD. Among the US Veteran's Administration population,nearly 86% of the incident dialysis patients had a hospital admissionwithin the five years preceding the admission. Of those, 63% werehospitalized at initiation of dialysis. This suggests a tremendousopportunity to intervene prior to dialysis.

Despite being further down the arterial tree than other organs, thekidneys receive a disproportionate amount of cardiac output at rest. Theglomerular membrane represents a path of least resistance of filtrateinto the tubules. In healthy states, the nephron has multiple,intricate, redundant means of auto-regulating within normal ranges ofarterial pressure.

Venous congestion has been implicated in reduced renal function and isassociated with the systemic hypervolemia found in later stages of CKD.Since the kidney is covered with a semi-rigid capsule, small changes invenous pressure translate into direct changes in the intratubulepressures. This shift in intratubule pressure has been shown toupregulate reabsorption of sodium and water, perpetuating the viciouscycle.

Regardless of the initial insult and early progression, more advancedCKD is associated with decreased filtration (by definition) and greaterazotemia. Regardless of whether the remaining nephrons arehyperabsorbing water or they are just unable to filtrate sufficiently,this nephron loss is associated with fluid retention and a progressivedecline in renal function.

The kidney is sensitive to subtle shifts in volume. As pressure ineither the tubule or capillary bed rises, the pressure in the otherfollows. As the capillary bed pressure rises, the production of filtrateand elimination of urine can decline dramatically. While not intendingto be bound by any theory, it is believe that mild and regulatednegative pressure delivered to the renal pelvis decreases the pressureamong each of the functioning nephrons. In healthy anatomy, the renalpelvis is connected via a network of calyces and collecting ducts toapproximately one million individual nephrons. Each of these nephronsare essentially fluid columns connecting Bowman's space to the renalpelvis. Pressure transmitted to the renal pelvis translates throughout.It is believed that, as negative pressure is applied to the renalpelvis, the glomerular capillary pressure forces more filtrate acrossthe glomerular membrane, leading to increased urine output.

It is important to note that the tissues of the urinary tract are linedwith urothelium, a type of transitional epithelium. The tissues liningthe inside of the urinary tract are also referred to as uroendothelialor urothelial tissues, such as mucosal tissue 1003 of the ureter and/orkidney and bladder tissue 1004. Urothelium has a very high elasticity,enabling a remarkable range of collapsibility and distensibility. Theurothelium lining the ureter lumen is surrounded first by the laminapropria, a thin layer of loose connective tissue, which togethercomprise the urothelial mucosa. This mucosa is then surrounded by alayer of longitudinal muscle fibers. These longitudinal muscle fiberssurrounding the urothelial mucosa and the elasticity of the urothelialmucosa itself allow the ureter to relax into a collapsed stellatecross-section and then expand to full distention during diuresis.Histology of any normal ureteral cross-section reveals this star-shapedlumen in humans and other mammals generally used in translationalmedical research. Wolf et al., “Comparative Ureteral Microanatomy”, JEU10: 527-31 (1996).

The process of transporting urine from the kidney to the bladder isdriven by contractions through the renal pelvis and peristalsis distallythrough the rest of the ureter. The renal pelvis is the widening of theproximal ureter into a funnel-shape where the ureter enters the kidney.The renal pelvis has actually been shown to be a continuation of theureter, comprised of the same tissue but with one additional musclelayer that allows it to contract. Dixon and Gosling, “The Musculature ofthe Human Renal Calyces, Pelvis and Upper Ureter”, J. Anat. 135: 129-37(1982). These contractions push urine through the renal pelvis funnel toallow peristaltic waves to propagate the fluid through the ureter to thebladder.

Imaging studies have shown that the ureter of the dog can readilyincrease to up to 17× its resting cross-sectional area to accommodatelarge volumes of urine during diuresis. Woodburne and Lapides, “TheUreteral Lumen During Peristalsis”, AJA 133: 255-8 (1972). Among swine,considered to be the closest animal model for the human upper urinarytract, the renal pelvis and most proximal ureter are actually shown tobe the most compliant of all ureteral sections. Gregersen, et al.,“Regional Differences Exist in Elastic Wall Properties in the Ureter”,SJUN 30: 343-8 (1996). Wolf's comparative analysis of various researchanimals' ureteral microanatomy to that of humans revealed comparablethickness of lamina propria layer relative to whole ureter diameter indogs (29.5% in humans and 34% in dogs) and comparable percentage ofsmooth muscle relative to total muscular cross sectional area in pigs(54% in humans and 45% in pigs). While there are certainly limitationsto the comparisons between species, dogs and pigs have historically beenstrong foci in studying and understanding human ureter anatomy andphysiology, and these reference values support this high level oftranslatability.

There is much more data available on structure and mechanics of pig anddog ureters and renal pelves than on human ureters. This is due partlyto the invasiveness required for such detailed analyses as well as theinherent limitations of various imaging modalities (MRI, CT, ultrasound,etc.) to attempt to accurately identify size and composition of suchsmall, flexible, and dynamic structures clinically. Nevertheless, thisability for the renal pelvis to distend or completely collapse in humansis a hurdle for nephrologists and urologists seeking to improve urineflow.

While not intending to be bound by any theory, the present inventorstheorized that the application of negative pressure might help tofacilitate fluid flow from the kidney, and that a very particular tool,designed to deploy a protective surface area in order to open ormaintain the opening of the interior of the renal pelvis whileinhibiting the surrounding tissues from contracting or collapsing intothe fluid column under negative pressure, is needed to facilitate theapplication of negative pressure within the renal pelvis. The catheterdesigns of the present invention disclosed herein provide a protectivesurface area to inhibit surrounding urothelial tissues from contractingor collapsing into the fluid column under negative pressure. It isbelieved that the catheter designs of the present invention disclosedherein can successfully maintain the stellate longitudinal folding ofthe ureteral wall away from the central axis and protected holes of thecatheter drainage lumen, and can inhibit natural sliding of the catheterdown the stellate cross-sectional area of the ureteral lumen and/ordownward migration by peristaltic waves.

Also, catheter designs of the present invention disclosed herein canavoid an unprotected open hole at the distal end of the drainage lumenwhich fails to protect surrounding tissues during suction. While it isconvenient to think of the ureter as a straight tube, the true ureterand renal pelvis can enter the kidney at a variety of angles. LippincottWilliams & Wilkins, Annals of Surgery, 58, FIGS. 3 & 9 (1913).Therefore, it would be difficult to control the orientation of anunprotected open hole at the distal end of the drainage lumen whendeploying such a catheter in the renal pelvis. This single hole maypresent a localized suction point that has no means of either reliableor consistent distancing from tissue walls, thereby permitting tissue toocclude the unprotected open hole and risking damage to the tissue.Also, catheter designs of the present invention disclosed herein canavoid placement of a balloon having an unprotected open hole at thedistal end of the drainage lumen close to the kidney which may result insuction against and/or occlusion of the calyces. Placement of a balloonhaving an unprotected open hole at the distal end of the drainage lumenat the very base of the uretero-renal pelvis junction may result insuction against and occlusion by renal pelvis tissue. Also, a roundedballoon may present a risk of ureteral avulsion or other damage fromincidental pulling forces on the balloon.

Delivering negative pressure into the kidney area of a patient has anumber of anatomical challenges for at least three reasons. First, theurinary system is composed of highly pliable tissues that are easilydeformed. Medical textbooks often depict the bladder as a thick muscularstructure that can remain in a fixed shape regardless of the volume ofurine contained within the bladder. However, in reality, the bladder isa soft deformable structure. The bladder shrinks to conform to thevolume of urine contained in the bladder. An empty bladder more closelyresembles a deflated latex balloon than a ball. In addition, the mucosallining on the interior of the bladder is soft and susceptible toirritation and damage. It is desirable to avoid drawing the urinarysystem tissue into the orifices of the catheter to maintain adequatefluid flow therethrough and avoid injury to the surrounding tissue.

Second, the ureters are small tube-like structures that can expand andcontract to transport urine from the renal pelvis to the bladder. Thistransport occurs in two ways: peristaltic activity and by a pressuregradient in an open system. In the peristaltic activity, a urine portionis pushed ahead of a contractile wave, which almost completelyobliterates the lumen. The wave pattern initiates in the renal pelvisarea, propagates along the ureter, and terminates in the bladder. Such acomplete occlusion interrupts the fluid flow and can prevent negativepressure delivered in the bladder from reaching the renal pelvis withoutassistance. The second type of transport, by pressure gradient through awide-open ureter, may be present during large urine flow. During suchperiods of high urine production, the pressure head in the renal pelviswould not need to be caused by contraction of the smooth muscles of theupper urinary tract, but rather is generated by the forward flow ofurine, and therefore reflects arterial blood pressure. Kiil F., “UrinaryFlow and Ureteral Peristalsis” in: Lutzeyer W., Melchior H. (Eds.)Urodynamics. Springer, Berlin, Heidelberg (pp. 57-70) (1973).

Third, the renal pelvis is at least as pliable as the bladder. The thinwall of the renal pelvis can expand to accommodate multiple times thenormal volume, for example as occurs in patients having hydronephrosis.

More recently, the use of negative pressure in the renal pelvis toremove blood clots from the renal pelvis by the use of suction has beencautioned against because of the inevitable collapse of the renalpelvis, and as such discourages the use of negative pressure in therenal pelvis region. Webb, Percutaneous Renal Surgery: A PracticalClinical Handbook. p 92. Springer (2016).

While not intending to be bound by any theory, the tissues of the renalpelvis and bladder are flexible enough to be drawn inwardly duringdelivery of negative pressure to conform to the shape and volume of thetool being used to deliver negative pressure. Analogous to the vacuumsealing of a husked ear of corn, the urothelial tissue will collapsearound and conform to the source of negative pressure. To prevent thetissue from occluding the lumen and impeding the flow of urine, thepresent inventors theorized that a protective surface area sufficient tomaintain the fluid column when mild negative pressure is applied wouldprevent or inhibit occlusion.

The present inventors determined that there are specific features thatenable a catheter tool to be deployed successfully in and delivernegative pressure through the urological region that have not beenpreviously described. These require a deep understanding of the anatomyand physiology of the treatment zone and adjacent tissues. The cathetermust comprise a protective surface area within the renal pelvis bysupporting the urothelium and inhibiting the urothelial tissue fromoccluding openings in the catheter during application of negativepressure through the catheter lumen. For example, establishing a threedimensional shape or void volume, that is free or essentially free fromurothelial tissue, ensures the patency of the fluid column or flow fromeach of the million nephrons into the drainage lumen of the catheter.

Since the renal pelvis is comprised of longitudinally oriented smoothmuscle cells, the protective surface area would ideally incorporate amulti-planar approach to establishing the protected surface area.Anatomy is often described in three planes, sagittal (vertical front toback that divides the body into right and left parts), coronal (verticalside to side dividing the body into dorsal and ventral parts) andtransverse (horizontal or axial that divides the body into superior andinferior parts, and is perpendicular to the sagittal and coronalplanes). The smooth muscle cells in the renal pelvis are orientedvertically. It is desirable for the catheter to also maintain a radialsurface area across the many transverse planes between the kidney andthe ureter. This enables a catheter to account for both longitudinal andhorizontal portions of the renal pelvis in the establishment of aprotective surface area 1001. In addition, given the flexibility of thetissues, the protection of these tissues from the openings or orificesthat lead to the lumen of the catheter tool is desirable. The cathetersdiscussed herein can be useful for delivering negative pressure,positive pressure, or can be used at ambient pressure, or anycombination thereof.

In some examples, a deployable/retractable expansion mechanism isutilized that, when deployed, creates and/or maintains a patent fluidcolumn or flow between the kidney and the catheter drainage lumen. Thisdeployable/retractable mechanism, when deployed, creates the protectivesurface area 1001 within the renal pelvis by supporting the urotheliumand inhibiting the urothelial tissue from occluding openings in thecatheter during application of negative pressure through the catheterlumen. In some examples, the retention portion is configured to beextended into a deployed position in which a diameter of the retentionportion is greater than a diameter of the drainage lumen portion.

With reference to FIGS. 1A-1C, 1F, 1P, 1U, 2A, 2B, 7A, 7B, 17, and 44,the urinary tract, indicated generally at 1, comprises a patient's rightkidney 2 and left kidney 4. As discussed above, the kidneys 2, 4 areresponsible for blood filtration and clearance of waste compounds fromthe body through urine. Urine produced by the right kidney 2 and theleft kidney 4 is drained into a patient's bladder 10 through tubules,namely a right ureter 6 and a left ureter 8. For example, urine may beconducted through the ureters 6, 8 by peristalsis of the ureter walls,as well as by gravity. The ureters 6, 8 enter the bladder 10 through aureter orifice or opening 16. The bladder 10 is a flexible andsubstantially hollow structure adapted to collect urine until the urineis excreted from the body. The bladder 10 is transitionable from anempty position (signified by reference line E) to a full position(signified by reference line F). When the bladder is in the emptyposition E, the bladder superior wall 70 can be positioned adjacent toand/or conform to the outer periphery 72, 1002 or protective surfacearea 1001 of the distal end 136 of the bladder catheter 56, 116, shownfor example in FIGS. 1A and 1B as mesh 57, in FIGS. 1C, 1U and 7A ascoil 1210, in FIG. 1F as a basket shaped structure or support cap 212 ofa bladder superior wall support 210, in FIG. 1P as an annular balloon310, and in FIG. 17 as funnel 116. Normally, when the bladder 10 reachesa substantially full state, urine is permitted to drain from the bladder10 to a urethra 12 through a urethral sphincter or opening 18 located ata lower portion of the bladder 10. Contraction of the bladder 10 can beresponsive to stresses and pressure exerted on a trigone region 14 ofthe bladder 10, which is the triangular region extending between theureteral openings 16 and the urethral opening 18. The trigone region 14is sensitive to stress and pressure, such that as the bladder 10 beginsto fill, pressure on the trigone region 14 increases. When a thresholdpressure on the trigone region 14 is exceeded, the bladder 10 begins tocontract to expel collected urine through the urethra 12.

Similarly, as shown in FIGS. 1A, 1B, 1C, 1F, 1P, 1U, 2A and 2B, forexample, the outer periphery 72, 1002 or protective surface area 1001 ofthe ureteral catheters 112, 114 of the present invention can supporttissue 1003 of the ureter and/or kidney to maintain patency of fluidflow between the kidney and the bladder of the patient.

In some examples, methods and systems 50, 100, as shown for example inFIGS. 1A, 1B, 1C, 1F, 1P, 1U, 2A, 2B, 7, 17, and 44, are provided forremoving fluid (such as urine) from a patient, the method comprising:deploying a ureteral stent 52, 54 (shown in FIG. 1A) or ureteralcatheter 112, 114 (shown in FIGS. 1B, 1C, 1F, 1P, 1U, 2A, 2B, 7, 17, and44) into a ureter 6, 8 of a patient to maintain patency of fluid flowbetween a kidney 2, 4 and a bladder 10 of the patient; and/or deployinga bladder catheter 56, 116 into the bladder 10 of the patient, whereinthe bladder catheter 56, 116 comprises a distal end 136 configured to bepositioned in a patient's bladder 10, a drainage lumen portion 140having a proximal end 117, and a sidewall 119 extending therebetween;and applying negative pressure to the proximal end 117 of the bladdercatheter 56, 116 and/or ureteral catheter(s) 112, 114 to induce negativepressure in a portion of the urinary tract of the patient to removefluid from the patient. In some examples, the method further comprisesdeploying a second ureteral stent or second ureteral catheter into asecond ureter or kidney of the patient to maintain patency of fluid flowbetween a second kidney and the bladder of the patient, as shown inFIGS. 1A, 1B, 1C, 1F, 1P, 1U, 2A, 2B, 7, 17, and 44. Specificcharacteristics of exemplary ureteral stents or ureteral catheters ofthe present invention are described in detail herein.

In some non-limiting examples, the ureteral or bladder catheter 56, 112,114, 116, 312, 412, 512, 812, 1212, 5000, 5001 comprises (a) a proximalportion 117, 128, 1228, 5006, 5007, 5017 and (b) a distal portion 118,318, 1218, 5004, 5005, the distal portion comprising a retention portion130, 330, 410, 500, 1230, 1330, 2230, 3230, 4230, 5012, 5013 thatcomprises one or more protected drainage holes, ports or perforations133, 533, 1233 and is configured to establish an outer periphery 1002 orprotective surface area 1001 that inhibits urothelial tissue, such asmucosal tissue 1003 of the ureter and/or kidney and bladder tissue 1004,from occluding the one or more protected drainage holes, ports orperforations 133, 533, 1233 upon application of negative pressurethrough the catheter.

Exemplary Ureteral Catheters:

As shown in FIGS. 2A, 7, 17, and 44, examples of systems 100 includingureteral catheters 112, 114 configured to be positioned within theurinary tract of a patient are illustrated. For example, distal ends120, 121, 1220, 5019, 5021 of the ureteral catheters 112, 114 can beconfigured to be deployed in at least one of the patient's ureters 2, 4;renal pelvis 20, 21 area of the kidneys 6, 8; or the kidneys 6, 8.

In some examples, suitable ureteral catheters are disclosed in U.S. Pat.No. 9,744,331, US Patent Application Publication No. US 2017/0021128 A1,U.S. patent application Ser. No. 15/687,064, and U.S. patent applicationSer. No. 15/687,083, each of which is incorporated by reference herein.

In some examples, the system 100 can comprise two separate ureteralcatheters, such as a first catheter 112 disposed in or adjacent to therenal pelvis 20 of the right kidney 2 and a second catheter 114 disposedin or adjacent to the renal pelvis 21 of the left kidney 4. Thecatheters 112, 114 can be separate for their entire lengths, or can beheld in proximity to one another by a clip, ring, clamp, or other typeof connection mechanism (e.g., connector) to facilitate placement orremoval of the catheters 112, 114. As shown in FIGS. 2A, 7, 17, 27 and44, the proximal end 113, 115 of each catheter 112, 114 is positionedwithin the bladder 10, or at the proximal end of the ureter near thebladder 10, such that the fluid or urine drains into the bladder. Insome examples, the proximal end 113, 115 of each catheter 112, 114 canbe in fluid communication with the distal portion or end 136 of abladder catheter 56, 116. In some examples, catheters 112, 114 can mergeor be connected together within the bladder to form a single drainagelumen that drains into the bladder 10.

As shown in FIG. 2A, in some examples, the proximal end 113, 115 of oneor both of the catheters 112, 114 can be positioned within the urethra12 and optionally connected to additional drainage tubing to drain fluidto the outside of the body of the patient. As shown in FIG. 2B, in someexamples, the proximal end 113, 115 of one or both of the catheters 112,114 can be positioned to extend from the urethra 12 outside of the bodyof the patient.

In other examples, the catheters 112, 114 can be inserted through orenclosed within another catheter, tube, or sheath along portions orsegments thereof to facilitate insertion and retraction of the catheters112, 114 from the patient's body. For example, a bladder catheter 116can be inserted over and/or along the same guidewire as the ureteralcatheters 112, 114, or within the same tubing used to insert theureteral catheters 112, 114.

With reference to FIGS. 1B, 1C, 1F, 1P, 1U, 2A, 2B, 7, 8A, and 8B, anexemplary ureteral catheter 112, 1212, 5000 can comprise at least oneelongated body or tube 122, 1222, 5009 the interior of which defines orcomprises one or more drainage channel(s) or lumen(s), such as drainagelumen 124, 1224, 5002. The tube 122, 1222, 5009 size can range fromabout 1 Fr to about 9 Fr (French catheter scale). In some examples, thetube 122, 1222, 5009 can have an external diameter ranging from about0.33 to about 3 mm, and an internal diameter ranging from about 0.165 toabout 2.39 mm. In one example, the tube 122 is 6 Fr and has an outerdiameter of 2.0±0.1 mm. The length of the tube 122, 1222, 5009 can rangefrom about 30 cm to about 120 cm depending on the age (e.g., pediatricor adult) and gender of the patient.

The tube 122, 1222, 5009 can be formed from a flexible and/or deformablematerial to facilitate advancing and/or positioning the tube 122, 1222,5009 in the bladder 10 and ureters 6, 8 (shown in FIGS. 2 and 7). Thecatheter material should be flexible and soft enough to avoid or reduceirritation of the renal pelvis and ureter, but should be rigid enoughthat the tube 122, 1222, 5009 does not collapse when the renal pelvis orother portions of the urinary tract exert pressure on the exterior ofthe tube 122, 1222, 5009, or when the renal pelvis and/or ureter aredrawn against the tube 122, 1222, 5009 during inducement of negativepressure. For example, the tube 122, 1222, 5009 or drainage lumen can beformed, at least in part, from one or more materials including copper,silver, gold, nickel-titanium alloy, stainless steel, titanium, and/orpolymer such as biocompatible polymer(s), polyurethane, polyvinylchloride, polytetrafluoroethylene (PTFE), latex, silicon coated latex,silicon, silicone, polyglycolide or poly(glycolic acid) (PGA),Polylactide (PLA), Poly(lactide-co-glycolide), Polyhydroxyalkanoates,Polycaprolactone and/or Poly(propylene fumarate). In one example, thetube 122, 1222, 5009 is formed from a thermoplastic polyurethane. Thetube 122, 1222, 5009 can also include or be impregnated with one or moreof copper, silver, gold, nickel-titanium alloy, stainless steel, andtitanium. In some examples, the tube 122, 1222, 5009 is impregnated withor formed from a material viewable by fluoroscopic imaging. For example,the biocompatible polymer which forms the tube 122, 1222, 5009 can beimpregnated with barium sulfate or a similar radiopaque material. Assuch, the structure and position of the tube 122, 1222, 5009 is visibleto fluoroscopy.

At least a portion or all of the interior or exterior of the catheter112, 1212, 5000, for example tube 122, 1222, 5009 can be coated with ahydrophilic coating to facilitate insertion and/or removal, and/or toenhance comfort. In some examples, the coating is a hydrophobic and/orlubricious coating. For example, suitable coatings can compriseComfortCoat® hydrophilic coating which is available from Koninklijke DSMN.V. or hydrophilic coatings comprising polyelectrolyte(s) such as aredisclosed in U.S. Pat. No. 8,512,795, which is incorporated herein byreference.

In some examples, as shown in FIG. 8B, for example, the tube 122 cancomprise: a distal portion 118 (e.g., a portion of the tube 122configured to be positioned in the ureter 6, 8 and renal pelvis 20, 21);a middle portion 126 (e.g., a portion of the tube 122 configured toextend from the distal portion 118 through the ureteral openings 16 intothe patient's bladder 10 and urethra 12); and a proximal portion 128(e.g., a portion of the tube 122 extending into the bladder 10, orurethra 12, or extending from the urethra 12 outside of the body of thepatient). In one example, the combined length of the proximal portion128 and the middle portion 126 of the tube 122 is about 54±2 cm. In someexamples, the tube 122 terminates in the bladder 10. In that case, fluiddrains from the proximal end of the ureteral catheter 112, 114 and isdirected from the body through the additional indwelling bladdercatheter. In other examples, the tube 122 terminates in the urethra 12,e.g., a bladder catheter is not required. In other examples, the tubeextends from the urethra 12 outside of the body of the patient, e.g., abladder catheter is not required.

Exemplary Ureteral Retention Portions:

Any of the retention portions disclosed herein can be formed from thesame material as the drainage lumen discussed above, and can be unitarywith or connected to the drainage lumen, or the retention portion can beformed from a different material, such as those that are discussed abovefor the drainage lumen, and connected thereto. For example, theretention portion can be formed from any of the aforementionedmaterials, for example a polymer such as polyurethane, flexiblepolyvinyl chloride, polytetrafluoroethylene (PTFE), latex, silicone,silicon, polyglycolide or poly(glycolic acid) (PGA), Polylactide (PLA),Poly(lactide-co-glycolide), Polyhydroxyalkanoates. Polycaprolactoneand/or Poly(propylene fumarate).

Generally, and as shown for example in FIGS. 2A-C, 8A, and 8B, thedistal portion 118 of the ureteral catheter 112 comprises a retentionportion 130 for maintaining the distal end 120 of the catheter 112 at adesired fluid collection position proximate to or within the renalpelvis 20, 21 of the kidney 2, 4. In some examples, the retentionportion 130 is configured to be flexible and bendable to permitpositioning of the retention portion 130 in the ureter and/or renalpelvis. The retention portion 130 is desirably sufficiently bendable toabsorb forces exerted on the catheter 112 and to prevent such forcesfrom being translated to the ureters. For example, if the retentionportion 130 is pulled in the proximal direction P (shown in FIG. 9A)toward the patient's bladder, the retention portion 130 can besufficiently flexible to begin to unwind or be straightened so that itcan be drawn through the ureter. Similarly, when the retention portion130 can be reinserted into the renal pelvis or other suitable regionwithin the ureter, it can be biased to return to its deployedconfiguration.

In some examples, the retention portion 130 is integral with the tube122. In that case, the retention portion 130 can be formed by impartinga bend or curl to the catheter body 122 that is sized and shaped toretain the catheter at a desired fluid collection location. Suitablebends or coils can include a pigtail coil, corkscrew coil, and/orhelical coil, such as are shown in FIGS. 1, 2A, 7A, and 8A-10G. Forexample, the retention portion 130 can comprise one or more radially andlongitudinally extending helical coils configured to contact andpassively retain the catheter 112 within the ureter 6, 8 proximate to orwithin the renal pelvis 20, 21, as shown for example in FIGS. 2A, 7A,and 8A-10G. In other examples, the retention portion 130 is formed froma radially flared or tapered portion of the catheter body 122. Forexample, the retention portion 130 can further comprise a fluidcollecting portion, as shown in FIGS. 17-41C, such as a tapered orfunnel-shaped inner surface 186. In other examples, the retentionportion 130 can comprise a separate element connected to and extendingfrom the catheter body or tube 122.

In some examples, the retention portion 130 can further comprise one ormore perforated sections, such as drainage holes, perforations or ports132, 1232 (shown, for example, in FIGS. 9A-9E, 10A, 10E, 11-14, 27, 32A,32B, 33, 34, and 39-41A-C). A drainage port 132 can be located, forexample, at the open distal end 120, 121 of the tube 122, as shown inFIG. 10D. In other examples, perforated sections and/or drainage ports132, 1232 are disposed along the sidewall 109 of the distal portion 118of the catheter tube 122, as shown in FIGS. 9A-9E, 10A, 10E, 11-14, 27,32A, 32B, 33, 34, and 41A-C, or within the material of the retentionportion, such as the sponge material of FIGS. 39 and 40. The drainageports or holes 132, 1232 can be used for assisting in fluid collectionby which fluid can flow into the drainage lumen for removal from thepatient's body. In other examples, the retention portion 130 is solely aretention structure and fluid collection and/or imparting negativepressure is provided by structures at other locations on the cathetertube 122.

In some examples, such as are shown in FIGS. 9B-E, 10D-G, 18B, 18C-E,20, 22A-35, 37B, 38A, 39B, 40A-41C, at least a portion of, most, or allof the drainage holes, ports or perforations 132, 1232 are positioned inthe ureteral catheter 112, 114 or bladder catheter 116 in protectedsurface areas or inner surface areas 1000, such that tissue 1004, 1003from the bladder or kidney does not directly contact or partially orfully occlude the protected drainage holes, ports or perforations 133.For example, as shown in FIGS. 2A-2C, 7A, 7B, 10F, 17, 18D, 24B, 29C,39B, 40B, and 41B, when negative pressure is induced in the ureterand/or renal pelvis, a portion of the mucosal tissue 1003 of the ureterand/or kidney may be drawn against the outer periphery 72, 1002 orprotective surface areas 1001 or outer regions of the retention portion130 and may partially or fully occlude some drainage holes, ports orperforations 134 positioned on the outer periphery 72, 1002 orprotective surface areas 1001 of the retention portion 130. Similarly,as shown in FIGS. 2A-2C, 7A, 7B, 10G, 17, 18E, 24C, 39C, 40C, and 41C,when negative pressure is induced in the bladder, a portion of thebladder tissue 1004, such as the transitional epithelial tissue lining,lamina propria connective tissue, muscularis propria and/or fattyconnective tissue, may be drawn against the outer periphery 72, 1002 orprotective surface areas 1001 or outer regions of the retention portion130 and may partially or fully occlude some drainage holes, ports orperforations 134 positioned on the outer periphery 1002 or protectivesurface areas 1001 or outer regions of the retention portion 130.

At least a portion of protected drainage ports 133 located on theprotected surface areas or inner surface areas 1000 of the retentionportion 130 would not be partially or fully occluded when such tissues1003, 1004 contact the outer periphery 72, 1002 or protective surfaceareas 1001 or outer regions of the retention portion 130. Further, riskof injury to the tissues 1003, 1004 from pinching or contact with thedrainage ports 133 can be reduced or ameliorated. The configuration ofthe outer periphery 72, 1002 or protective surface areas 1001 or outerregions of the retention portion 130 depends upon the overallconfiguration of the retention portion 130. Generally, the outerperiphery 72, 1002 or protective surface areas 1001 or outer regions ofthe retention portion 130 contacts and supports the bladder 1004 orkidney tissue 1003, and thereby inhibits occlusion or blockage of theprotected drainage holes, ports or perforations 133.

For example, as shown in FIG. 10E-G, there is shown an exemplaryretention portion 1230 comprising a plurality of helical coils 1280,1282, 1284. The outer periphery 1002 or protective surface areas 1001 orouter regions of the helical coils 1280, 1282, 1284 contact and supportthe bladder tissue 1004 or kidney tissue 1003 to inhibit occlusion orblockage of protected drainage holes, ports or perforations 1233positioned in protected surface areas or inner surface areas 1000 of thehelical coils 1280, 1282, 1284. The outer periphery 1002 or protectivesurface areas 1001 or outer regions of the helical coils 1280, 1282,1284 provides protection for the protected drainage holes, ports orperforations 1233. In FIG. 10F, the kidney tissue 1003 is shownsurrounding and contacting at least a portion of the outer periphery1002 or protective surface areas 1001 or outer regions of the helicalcoils 1280, 1282, 1284, which inhibits contact of the kidney tissue 1003with the protected surface areas or inner surface areas 1000 of thehelical coils 1280, 1282, 1284, and thereby inhibits partial or fullblockage of the protected drainage holes, ports or perforations 1233 bythe kidney tissue 1003. In FIG. 10G, the bladder tissue 1004 is shownsurrounding and contacting at least a portion of the outer periphery1002 or protective surface areas 1001 or outer regions of the helicalcoils 1280, 1282, 1284, which inhibits contact of the bladder tissue1004 with the protected surface areas or inner surface areas 1000 of thehelical coils 1280, 1282, 1284, and thereby inhibits partial or fullblockage of the protected drainage holes, ports or perforations 1233 bythe bladder tissue 1004.

Similarly, other examples of configurations of bladder and/or ureteralretention portions shown in FIGS. 1, 2A, 7A, 17, 18A, 18B, 18C, 19, 20,21, 22A, 22B, 23A, 23B, 24, 25, 26, 27, 28A, 28B, 29A, 29B, 30, 31, 32A,32B, 33, 34, 35A, 35B, 36, 37A, 37B, 38A, 38B, 39, 40, and 41 provide anouter periphery 1002 or protective surface areas 1001 or outer regionswhich can contact and support the bladder tissue 1004 or kidney tissue1003 to inhibit occlusion or blockage of protected drainage holes, portsor perforations 133, 1233 positioned in protected surface areas or innersurface areas 1000 of the retention portions. Each of these exampleswill be discussed further below.

Referring now to FIGS. 8A, 8B, and 9A-9E, exemplary retention portions130 for ureteral catheters or bladder catheters comprising a pluralityof helical coils, such as one or more full coils 184 and one or morehalf or partial coils 183, are illustrated. The retention portion 130 iscapable of moving between a contracted position and the deployedposition with the plurality of helical coils. For example, asubstantially straight guidewire can be inserted through the retentionportion 130 to maintain the retention portion 130 in a substantiallystraight contracted position. When the guidewire is removed, theretention portion 130 can transition to its coiled configuration. Insome examples, the coils 183, 184 extend radially and longitudinallyfrom the distal portion 118 of the tube 122. With specific reference toFIGS. 8A and 8B, in an exemplary embodiment, the retention portion 130comprises two full coils 184 and one half coil 183. For example, asshown in FIGS. 8A and 8B, the outer diameter of the full coils 184,shown by line D1, can be about 18±2 mm, the half coil 183 diameter D2can be about 14 mm±2 mm, and the coiled retention portion 130 can have aheight H of about 16±2 mm.

The retention portion 130 can further comprise the one or more drainageholes 132, 1232 (shown in FIGS. 9A-9E, 10A and 10E, for example)configured to draw fluid into an interior of the catheter tube 122. Insome examples, the retention portion 130 can comprise two, three, four,five, six, seven, eight or more drainage holes 132, 1232, plus anadditional hole 110 at the distal tip or end 120 of the retentionportion. In some examples, the diameter of each of the drainage holes132, 1232 (shown in FIGS. 9A-9E, 10A and 10E, for example) can rangefrom about 0.7 mm to 0.9 mm and, preferably, is about 0.83±0.01 mm. Insome examples, the diameter of the additional hole 110 at the distal tipor end of the retention portion 130 (shown in FIGS. 9A-9E, 10A and 10E,for example) can range from about 0.165 mm to about 2.39 mm, or about0.7 to about 0.97 mm. The distance between adjacent drainage holes 132,specifically the linear distance between the closest outer edges ofadjacent drainage holes 132, 1232 when the coils are straightened, canbe about 15 mm±2.5 mm, or about 22.5±2.5 mm or more.

As shown in FIGS. 9A-9E, in another exemplary embodiment, the distalportion 118 of the drainage lumen 124 proximal to the retention portion130 defines a straight or curvilinear central axis L. In some examples,at least a half or first coil 183 and a full or second coil 184 of theretention portion 130 extend about an axis A of the retention portion130. The first coil 183 initiates or begins at a point where the tube122 is bent at an angle α ranging from about 15 degrees to about 75degrees from the central axis L, as indicated by angle α, and preferablyabout 45 degrees. As shown in FIGS. 9A and 9B, prior to insertion in thebody, the axis A can be coextensive with the longitudinal central axisL. In other examples, as shown in FIGS. 9C-9E, prior to insertion in thebody, the axis A extends from and is curved or angled, for example atangle β, relative to the central longitudinal axis L.

In some examples, multiple coils 184 can have the same or differentinner and/or outer diameter D and height H2 between adjacent coils 184.In that case, the outer diameter D1 of each of the coils 184 may rangefrom about 10 mm to about 30 mm. The height H2 between each of theadjacent coils 184 may range from about 3 mm to about 10 mm.

In other examples, the retention portion 130 is configured to beinserted in the tapered portion of the renal pelvis. For example, theouter diameter D1 of the coils 184 can increase toward the distal end120 of the tube 122, resulting in a helical structure having a taperedor partially tapered configuration. For example, the distal or maximumouter diameter D of the tapered helical portion ranges from about 10 mmto about 30 mm, which corresponds to the dimensions of the renal pelvis,and the outer diameter D1 of each adjacent coil can decrease closer tothe proximal end 128 of the retention portion 130. The overall height Hof the retention portion 130 can range from about 10 mm to about 30 mm.

In some examples, the outer diameter D1 of each coil 184 and/or heightH2 between each of the coils 184 can vary in a regular or irregularfashion. For example, the outer diameter D1 of coils or height H2between adjacent coils can increase or decrease by a regular amount(e.g., about 10% to about 25% between adjacent coils 184). For example,for a retention portion 130 having three coils (as shown, for example,in FIGS. 9A and 9B) an outer diameter D2 of a proximal-most coil orfirst coil 183 can be about 6 mm to 18 mm, an outer diameter D3 of amiddle coil or second coil 185 can be about 8 mm to about 24 mm, and anouter diameter D13 of a distal-most or third coil 187 can be betweenabout 10 mm and about 30 mm.

The retention portion 130 can further comprise the drainageperforations, holes or ports 132 disposed on or through the sidewall 109of the catheter tube 122 on, or adjacent to, the retention portion 130to permit urine waste to flow from the outside of the catheter tube 122to the inside drainage lumen 124 of the catheter tube 122. The positionand size of the drainage ports 132 can vary depending upon the desiredflow rate and configuration of the retention portion 130. The diameterD11 of each of the drainage ports 132 can range independently from about0.005 mm to about 1.0 mm. The spacing D12 between the closest edge ofeach of the drainage ports 132 can range independently from about 1.5 mmto about 5 mm. The drainage ports 132 can be spaced in any arrangement,for example, random, linear or offset. In some examples, the drainageports 132 can be non-circular, and can have a surface area of about0.00002 to 0.79 mm².

In some examples, as shown in FIG. 9A, the drainage ports 132 arelocated around the entire outer periphery 72, 1002 or protective surfacearea 1001 of the sidewall 109 of the catheter tube 122 to increase anamount of fluid that can be drawn into the drainage lumen 124 (shown inFIGS. 2, 9A, and 9B). In other examples, as shown in FIGS. 9B-9E and10-10E, the drainage holes, ports or perforations 132 can be disposedessentially only or only on the protected surface areas or inner surfaceareas 1000 or radially inwardly facing side 1286 of the coils 184 toprevent occlusion or blockage of the drainage ports 132, 1232 and theoutwardly facing side 1288 of the coils may be essentially free ofdrainage ports 132, 1232 or free of drainage ports 132, 1232. The outerperiphery 72, 189, 1002 or protective surface area 1001 or outer regions192 of the helical coils 183, 184, 1280, 1282, 1284 can contact andsupport the bladder tissue 1004 or kidney tissue 1003 to inhibitocclusion or blockage of protected drainage holes, ports or perforations133, 1233 positioned in protected surface areas or inner surface areas1000 of the helical coils 183, 184, 1280, 1282, 1284. For example, whennegative pressure is induced in the ureter and/or renal pelvis, mucosaltissue of the ureter and/or kidney may be drawn against the retentionportion 130 and may occlude some drainage ports 134 on the outerperiphery 72, 189, 1002 of the retention portion 130. Drainage ports133, 1233 located on the radially inward side 1286 or protected surfaceareas or inner surface areas 1000 of the retention structure would notbe appreciably occluded when such tissues 1003, 1004 contact the outerperiphery 72, 189, 1002 or protective surface area 1001 or outer regionsof the retention portion 130. Further, risk of injury to the tissuesfrom pinching or contact with the drainage ports 132, 133, 1233, orprotected drainage holes, ports or perforations 133, 1233 can be reducedor ameliorated.

With reference to FIGS. 9C and 9D, other examples of ureteral catheters112 having a retention portion 130 comprising a plurality of coils 184are illustrated. As shown in FIG. 9C, the retention portion 130comprises three coils 184 extending about the axis A. The axis A is acurved arc extending from the central longitudinal axis L of the portionof the drainage lumen 181 proximal to the retention portion 130. Thecurvature imparted to the retention portion 130 can be selected tocorrespond to the curvature of the renal pelvis, which comprises acornucopia-shaped cavity.

As shown in FIG. 9D, in another exemplary embodiment, the retentionportion 130 can comprise two coils 184 extending about an angled axis A.The angled axis A extends at an angle from a central longitudinal axisL, and is angled, as shown by angle β, relative to an axis generallyperpendicular to the central axis L of the portion of the drainagelumen. The angle β can range from about 15 to about 75 degrees (e.g.,about 105 to about 165 degrees relative to the central longitudinal axisL of the drainage lumen portion of the catheter 112).

FIG. 9E shows another example of a ureteral catheter 112. The retentionportion comprises three helical coils 184 extending about an axis A. Theaxis A is angled, as shown by angle β, relative to the horizontal. As inthe previously-described examples, the angle β can range from about 15to about 75 degrees (e.g., about 105 to about 165 degrees relative tothe central longitudinal axis L of the drainage lumen portion of thecatheter 112).

In some examples shown in FIGS. 10-10E, the retention portion 1230 isintegral with the tube 1222. In other examples, the retention portion1230 can comprise a separate tubular member connected to and extendingfrom the tube or drainage lumen 1224.

In some examples, the retention portion comprises a plurality ofradially extending coils 184. The coils 184 are configured in the shapeof a funnel, and thereby form a funnel support. Some examples of coilfunnel supports are shown in FIGS. 2A-C, 7A, 7B, 8A, and 8A-10E.

In some examples, the at least one sidewall 119 of the funnel supportcomprises at least a first coil 183 having a first diameter and a secondcoil 184 having a second diameter, the first diameter being less thanthe second diameter, wherein the maximum distance between a portion of asidewall of the first coil and a portion of an adjacent sidewall of thesecond coil ranges from about 0 mm to about 10 mm. In some examples, thefirst diameter of the first coil 183 ranges from about 1 mm to about 10mm and the second diameter of the second coil 184 ranges from about 5 mmto about 25 mm. In some examples, the diameter of the coils increasestoward a distal end of the drainage lumen, resulting in a helicalstructure having a tapered or partially tapered configuration. In someembodiments, the second coil 184 is closer to an end of the distalportion 118 of the drainage lumen 124 than is the first coil 183. Insome examples, the second coil 184 is closer to an end of the proximalportion 128 of the drainage lumen 124 than is the first coil 183.

In some examples, the at least one sidewall 119 of the funnel supportcomprises an inwardly facing side 1286 and an outwardly facing side1288, the inwardly facing side 1286 comprising at least one opening 133,1233 for permitting fluid flow into the drainage lumen, the outwardlyfacing side 1288 being essentially free of or free of openings, asdiscussed below. In some examples, the at least one opening 133, 1233has an area ranging from about 0.002 mm² to about 100 mm².

In some examples, the first coil 1280 comprises a sidewall 119comprising a radially inwardly facing side 1286 and a radially outwardlyfacing side 1288, the radially inwardly facing side 1286 of the firstcoil 1280 comprising at least one opening 1233 for permitting fluid flowinto the drainage lumen.

In some examples, the first coil 1280 comprises a sidewall 119comprising a radially inwardly facing side 1286 and a radially outwardlyfacing side 1288, the radially inwardly facing side 1286 of the firstcoil 1280 comprising at least two openings 1233 for permitting fluidflow into the drainage lumen 1224.

In some examples, the first coil 1280 comprises a sidewall 119comprising a radially inwardly facing side 1286 and a radially outwardlyfacing side 1288, the radially outwardly facing side 1288 of the firstcoil 1280 being essentially free of or free of one or more openings1232.

In some examples, the first coil 1280 comprises a sidewall 119comprising a radially inwardly facing side 1286 and a radially outwardlyfacing side 1288, the radially inwardly facing side 1286 of the firstcoil 1280 comprising at least one opening 1233 for permitting fluid flowinto the drainage lumen 1224 and the radially outwardly facing side 1288being essentially free of or free of one or more openings 1232.

Referring now to FIGS. 10-10E, in some examples, the distal portion 1218comprises an open distal end 1220 for drawing fluid into the drainagelumen 1224. The distal portion 1218 of the ureteral catheter 1212further comprises a retention portion 1230 for maintaining the distalportion 1218 of the drainage lumen or tube 1222 in the ureter and/orkidney. In some examples, the retention portion 1230 comprises aplurality of radially extending coils 1280, 1282, 1284. The retentionportion 1230 can be flexible and bendable to permit positioning of theretention portion 1230 in the ureter, renal pelvis, and/or kidney. Forexample, the retention portion 1230 is desirably sufficiently bendableto absorb forces exerted on the catheter 1212 and to prevent such forcesfrom being translated to the ureters. Further, if the retention portion1230 is pulled in the proximal direction P (shown in FIGS. 9A-9E) towardthe patient's bladder 10, the retention portion 1230 can be sufficientlyflexible to begin to unwind or be straightened so that it can be drawnthrough the ureter 6, 8. In some examples, the retention portion 1230 isintegral with the tube 1222. In other examples, the retention portion1230 can comprise a separate tubular member connected to and extendingfrom the tube or drainage lumen 1224. In some examples, the catheter1212 comprises a radiopaque band 1234 (shown in FIG. 29) positioned onthe tube 1222 at a proximal end of the retention portion 1230. Theradiopaque band 1234 is visible by fluoroscopic imaging duringdeployment of the catheter 1212. In particular, a user can monitoradvancement of the band 1234 through the urinary tract by fluoroscopy todetermine when the retention portion 1230 is in the renal pelvis andready for deployment.

In some examples, the retention portion 1230 comprises perforations,drainage ports, or openings 1232 in a sidewall of the tube 1222. Asdescribed herein, a position and size of the openings 1232 can varydepending upon a desired volumetric flow rate for each opening and sizeconstraints of the retention portion 1230. In some examples, a diameterD11 of each of the openings 1232 can range independently from about 0.05mm to about 2.5 mm and have an area of about 0.002 mm² to about 5 mm².Openings 1232 can be positioned extending along on a sidewall 119 of thetube 1222 in any direction desired, such as longitudinal and/or axial.In some examples, spacing between the closest adjacent edge of each ofthe openings 1232 can range from about 1.5 mm to about 15 mm. Fluidpasses through one or more of the perforations, drainage ports, oropenings 1232 and into the drainage lumen 1234. Desirably, the openings1232 are positioned so that they are not occluded by tissues 1003 of theureters 6, 8 or kidney when negative pressure is applied to the drainagelumen 1224. For example, as described herein, openings 1233 can bepositioned on interior portions or protected surfaces areas 1000 ofcoils or other structures of the retention portion 1230 to avoidocclusion of the openings 1232, 1233. In some examples, the middleportion 1226 and proximal portion 1228 of the tube 1222 can beessentially free of or free from perforations, ports, openings oropenings to avoid occlusion of openings along those portions of the tube1222. In some examples, a portion 1226, 1228 which is essentially freefrom perforations or openings includes substantially fewer openings 1232than other portions such as distal portion 1218 of the tube 1222. Forexample, a total area of openings 1232 of the distal portion 1218 may begreater than or substantially greater than a total area of openings ofthe middle portion 1226 and/or the proximal portion 1228 of the tube1222.

In some examples, the openings 1232 are sized and spaced to improvefluid flow through the retention portion 1230. In particular, thepresent inventors have discovered that when a negative pressure isapplied to the drainage lumen 1224 of the catheter 1212 a majority offluid is drawn into the drainage lumen 1224 through proximal-mostperforations or openings 1232. In order to improve flow dynamics so thatfluid is also received through more distal openings and/or through theopen distal end 1220 of the tube 1222, larger size or a greater numberof openings 1232 can be provided towards the distal end 1220 of theretention portion 1230. For example, a total area of openings 1232 on alength of tube 1222 near a proximal end 1228 of the retention portion1230 may be less than a total area of openings 1232 of a similar sizedlength of the tube 1222 located near the open distal end 1220 of thetube 1222. In particular, it may be desirable to produce a flowdistribution through the drainage lumen 1224 in which less than 90%,preferably less than 70%, and, more preferably, less than 55% of fluidflow is drawn into the drainage lumen 1224 through a single opening 1232or a small number of openings 1232 positioned near the proximal end 1228of the retention portion 1230.

In many examples, the openings 1232 are generally a circular shape,although triangular, elliptical, square-shaped, diamond shaped, and anyother opening shapes may also be used. Further, as will be appreciatedby one of ordinary skill in the art, a shape of the openings 1232 maychange as the tube 1222 transitions between an uncoiled or elongatedposition and a coiled or deployed position. It is noted that while theshape of the openings 1232 may change (e.g., the orifices may becircular in one position and slightly elongated in the other position),the area of the openings 1232 is substantially similar in the elongatedor uncoiled position compared to the deployed or coiled position.

In some examples, the drainage lumen 1224 defined by tube 1222comprises: a distal portion 1218 (e.g., a portion of the tube 1222configured to be positioned in the ureter 6, 8 and renal pelvis 20, 21(shown for example in FIGS. 7A and 10)); a middle portion 1226 (e.g., aportion of the tube 1222 configured to extend from the distal portionthrough ureteral openings 16 into the patient's bladder 10 and urethra12 (shown in FIGS. 7A and 10)); and a proximal portion 1228 (e.g., aportion of the tube 1222 extending from the urethra 12 to an externalfluid collection container and/or pump 2000). In one example, thecombined length of the proximal portion 1228 and the middle portion 1226of the tube 1222 is about 54±2 cm. In some examples, the middle portion1226 and proximal portion 1228 of the tube 1222 includes distancemarkings 1236 (shown in FIG. 10) on a sidewall of the tube 1222 whichcan be used, during deployment of the catheter 1212, to determine howfar the tube 1222 is inserted into the urinary tract of the patient.

As shown in FIGS. 7A and 10-14, an exemplary ureteral catheter 1212comprises at least one elongated body or tube 1222, the interior ofwhich defines or comprises one or more drainage channel(s) or lumen(s),such as drainage lumen 1224. The tube 1222 size can range from about 1Fr to about 9 Fr (French catheter scale). In some examples, the tube1222 can have an external diameter ranging from about 0.33 to about 3.0mm, and an internal diameter ranging from about 0.165 to about 2.39 mm.In one example, the tube 1222 is 6 Fr and has an outer or externaldiameter of 2.0±0.1 mm. The overall length of the tube 1222 can rangefrom about 30 cm to about 120 cm depending on the age (e.g., pediatricor adult) and gender of the patient.

The tube 1222 can be formed from a flexible and/or deformable materialto facilitate advancing and/or positioning the tube 1222 in the bladder10 and ureters 6, 8 (shown in FIG. 7), such as any of the materialsdiscussed above. For example, the tube 1222 can be formed from one ormore materials such as biocompatible polymers, polyvinyl chloride,polytetrafluoroethylene (PTFE) such as Teflon®, silicon coated latex, orsilicon. In one example, the tube 1222 is formed from a thermoplasticpolyurethane.

Helical Coil Retention Portion

Referring now to FIGS. 10A-10E, an exemplary retention portion 1230comprises helical coils 1280, 1282, 1284. In some examples, theretention portion 1230 comprises a first or half coil 1280 and two fullcoils, such as a second coil 1282 and a third coil 1284. As shown inFIGS. 10A-10D, in some examples, the first coil 1280 comprises a halfcoil extending from 0 degrees to 180 degrees around a curvilinearcentral axis A of the retention portion 1230. In some examples, as shownthe curvilinear central axis A is substantially straight andco-extensive with a curvilinear central axis of the tube 1222. In otherexamples, the curvilinear central axis A of the retention portion 1230can be curved giving the retention portion 1230, for example, acornucopia shape. The first coil 1280 can have a diameter D1 of about 1mm to 20 mm and preferably about 8 mm to 10 mm. The second coil 1282 canbe a full coil extending from 180 degrees to 540 degrees along theretention portion 1230 having a diameter D2 of about 5 mm to 50 mm,preferably about 10 mm to 20 mm, and more preferably about 14 mm±2 mm.The third coil 1284 can be a full coil extending between 540 degrees and900 degrees and having a diameter D3 of between 5 mm and 60 mm,preferably about 10 mm to 30 mm, and more preferably about 18 mm±2 mm.In other examples, multiple coils 1282, 1284 can have the same innerand/or outer diameter. For example, an outer diameter of the full coils1282, 1284, can each be about 18±2 mm.

In some examples, an overall height H of the retention portion 1230ranges from about 10 mm to about 30 mm and, preferably about 18±2 mm. Aheight H2 of a gap between adjacent coils 1284, namely between thesidewall 1219 of the tube 1222 of the first coil 1280 and the adjacentsidewall 1221 of the tube 122 of the second coil 1282 is less than 3.0mm, preferably between about 0.25 mm and 2.5 mm, and more preferablybetween about 0.5 mm and 2.0 mm.

The retention portion 1230 can further comprise a distal-most curvedportion 1290. For example, the distal most portion 1290 of the retentionportion 1230, which includes the open distal end 1220 of the tube 1222,can be bent inwardly relative to a curvature of the third coil 1284. Forexample, a curvilinear central axis X1 (shown in FIG. 10D) of thedistal-most portion 1290 can extend from the distal end 1220 of the tube1222 towards the curvilinear central axis A of the retention portion1230.

The retention portion 1230 is capable of moving between a contractedposition, in which the retention portion 1230 is straight for insertioninto the patient's urinary tract, and the deployed position, in whichthe retention portion 1230 comprises the helical coils 1280, 1282, 1284.Generally, the tube 1222 is naturally biased toward the coiledconfiguration. For example, an uncoiled or substantially straightguidewire can be inserted through the retention portion 1230 to maintainthe retention portion 1230 in its straight contracted position, as shownfor example in FIGS. 11-14. When the guidewire is removed, the retentionportion 1230 naturally transitions to its coiled position.

In some examples, the openings 1232, 1233 are disposed essentially onlyor only on a radially inwardly facing side 1286 or protected surfacearea or inner surface area 1000 of the coils 1280, 1282, 1284 to preventocclusion or blockage of the openings 1232, 1233. A radially outwardlyfacing side 1288 of the coils 1280, 1282, 1284 may be essentially freeof the openings 1232. In similar examples, a total area of openings1232, 1233 on the inwardly facing side 1286 of the retention portion1230 can be substantially greater than a total area of openings 1232 onthe radially outwardly facing side 1288 of the retention portion 1230.Accordingly, when negative pressure is induced in the ureter and/orrenal pelvis, mucosal tissue of the ureter and/or kidney may be drawnagainst the retention portion 1230 and may occlude some openings 1232 onthe outer periphery 1002 or protective surface area 1001 of theretention portion 1230. However, openings 1232 located on the radiallyinward side 1286 or protected surface area or inner surface area 1000 ofthe retention portion 1230 are not appreciably occluded when suchtissues contacts the outer periphery 1002 or protective surface area1001 of the retention portion 1230. Therefore, risk of injury to thetissues from pinching or contact with the drainage openings 1232 can bereduced or eliminated.

Hole or Opening Distribution Examples

In some examples, the first coil 1280 can be free or essentially freefrom openings 1232. For example, a total area of openings 1232 on thefirst coil 1280 can be less than or substantially less than a total areaof openings 1232 of the full coils 1282, 1284. Examples of variousarrangements of openings or openings 1232, which could be used for acoiled retention portion (such as coiled retention portion 1230 shown inFIGS. 10A-10E), are illustrated in FIGS. 11-14. As shown in FIGS. 11-14,a retention portion 1330 is depicted in its uncoiled or straightposition, as occurs when a guidewire is inserted through the drainagelumen.

An exemplary retention portion 1330 is illustrated in FIG. 11. In orderto more clearly describe positioning of openings of the retentionportion 1330, the retention portion 1330 is referred to herein as beingdivided into a plurality of sections or perforated sections, such as aproximal-most or first section 1310, a second section 1312, a thirdsection 1314, a fourth section 1316, a fifth section 1318, and adistal-most or sixth section 1320. One of ordinary skill in the artwould understand that fewer or additional sections can be included, ifdesired. As used herein, “section” refers to a discrete length of thetube 1322 within the retention portion 1330. In some examples, sectionsare equal in length. In other examples, some sections can have the samelength, and other sections can have a different length. In otherexamples, each section has a different length. For example, each ofsections 1310, 1312, 1314, 1316, 1318 and 1320 can have a length L1-L6,respectively, ranging from about 5 mm to about 35 mm, and preferablyfrom about 5 mm to 15 mm.

In some examples, each section 1310, 1312, 1314, 1316, 1318 and 1320comprises one or more openings 1332. In some examples, each section eachcomprises a single opening 1332. In other examples, the first section1310 includes a single opening 1332 and other sections comprise multipleopenings 1332. In other examples, different sections comprise one ormore openings 1332, each of the opening(s) having a different shape ordifferent total area.

In some examples, such as the retention portion 1230 shown in FIGS.10A-10E, the first or half coil 1280, which extends from 0 to about 180degrees of the retention portion 1230 can be free from or essentiallyfree from openings. The second coil 1282 can include the first section1310 extending between about 180 and 360 degrees. The second coil 1282can also include the second and third sections 1312, 1314 positionedbetween about 360 degrees and 540 degrees of the retention portion 1230.The third coil 1284 can include the fourth and fifth sections 1316, 1318positioned between about 540 degrees and 900 degrees of the retentionportion 1230.

In some examples, the openings 1332 can be sized such that a total areaof openings of the first section 1310 is less than a total area ofopenings of the adjacent second section 1312. In a similar manner, ifthe retention portion 1330 further comprises a third section 1314, thenopenings of a third section 1314 can have a total area that is greaterthan the total area of the openings of the first section 1310 or thesecond section 1312. Openings of the forth 1316, fifth 1318, and sixth1320 sections may also have a gradually increasing total area and/ornumber of openings to improve fluid flow through the tube 1222.

As shown in FIG. 11, the retention portion 1230 of the tube includesfive sections 1310, 1312, 1314, 1316, 1318, each of which includes asingle opening 1332, 1334, 1336, 1338, 1340. The retention portion 1330also includes a sixth section 1320 which includes the open distal end1220 of the tube 1222. In this example, the opening 1332 of the firstsection 1310 has the smallest total area. For example, a total area ofthe opening 1332 of the first section can range from about 0.002 mm² andabout 2.5 mm², or about 0.01 mm² and 1.0 mm², or about 0.1 mm² and 0.5mm². In one example, the opening 1332 is about 55 mm from the distal end1220 of the catheter, has a diameter of 0.48 mm, and an area of 0.18mm². In this example, a total area of openings 1334 of the secondsection 1312 is greater than the total area of openings 1232 of thefirst section 1310 and can range in size from about 0.01 mm² to about1.0 mm². The third 1336, fourth 1338, and fifth 1350 openings can alsorange in size from about 0.01 mm² to about 1.0 mm². In one example, thesecond opening 1334 is about 45 mm from the distal end of the catheter1220, has a diameter of about 0.58 mm, and an area of about 0.27 mm².The third opening 1336 can be about 35 mm from the distal end of thecatheter 1220 and have a diameter of about 0.66 mm. The fourth opening1338 can be about 25 mm from the distal end 1220 and have a diameter ofabout 0.76 mm. The fifth opening 1340 can be about 15 mm from the distalend 1220 of the catheter and have a diameter of about 0.889 mm. In someexamples, the open distal end 1220 of the tube 1222 has the largestopening having an area ranging from about 0.5 mm² to about 5.0 mm² ormore. In one example, the open distal end 1220 has a diameter of about0.97 mm and an area of about 0.74 mm².

As described herein, openings 1332 1334, 1336, 1338, 1340 can bepositioned and sized so that a volumetric flow rate of fluid passingthrough the first opening 1332 more closely corresponds to a volumetricflow rate of openings of more distal sections, when negative pressure isapplied to the drainage lumen 1224 of the catheter 1212, for examplefrom the proximal portion 1228 of the drainage lumen 1224. As describedabove, if each opening were the same area, then, when negative pressureis applied to the drainage lumen 1224, the volumetric flow rate of fluidpassing through the proximal-most of first opening 1332 would besubstantially greater than a volumetric flow rate of fluid passingthrough openings 1334 closer to the distal end 1220 of the retentionportion 1330. While not intending to be bound by any theory, it isbelieved that when negative pressure is applied, the pressuredifferential between the interior of the drainage lumen 1224 andexternal to the drainage lumen 1224 is greater in the region of theproximal-most opening and decreases at each opening moving towards thedistal end of the tube. For example, sizes and positions of the openings1332 1334, 1336, 1338, 1340 can be selected so that a volumetric flowrate for fluid which flows into openings 1334 of the second section 1312is at least about 30% of a volumetric flow rate of fluid which flowsinto the opening(s) 1332 of the first section 1310. In other examples, avolumetric flow rate for fluid flowing into the proximal-most or firstsection 1310 is less than about 60% of a total volumetric flow rate forfluid flowing through the proximal portion of the drainage lumen 1224.In other examples, a volumetric flow rate for fluid flowing intoopenings 1332, 1334 of the two proximal-most sections (e.g., the firstsection 1310 and the second section 1312) can be less than about 90% ofa volumetric flow rate of fluid flowing through the proximal portion ofthe drainage lumen 1224 when a negative pressure, for example a negativepressure of about −45 mmHg, is applied to the proximal end of thedrainage lumen.

As will be appreciated by one of ordinary skill in the art, volumetricflow rate and distribution for a catheter or tube comprising a pluralityof openings or perforations can be directly measured or calculated in avariety of different ways. As used herein, “volumetric flow rate” meansactual measurement of the volumetric flow rate downstream and adjacentto each opening or using a method for “Calculated Volumetric Flow Rate”described below.

For example, actual measurement of the dispersed fluid volume over timecan be used to determine the volumetric flow rate through each opening1332, 1334, 1336, 1338, 1340. In one exemplary experimental arrangement,a multi-chamber vessel comprising individual chambers sized to receivesections 1310, 1312, 1314, 1316, 1318, 1320 of the retention portion1330 could be sealed around and enclose the retention portion 1330. Eachopening 1332, 1334, 1336, 1338, 1340 could be sealed in one of thechambers. An amount of fluid volume drawn from the respective chamberinto the tube 3222 through each opening 1332, 1334, 1336, 1338, 1340could be measured to determine an amount of fluid volume drawn into eachopening over time when a negative pressure is applied. The cumulativeamount of fluid volume collected in the tube 3222 by a negative pressurepump system would be equivalent to the sum of fluid drawn into eachopening 1332, 1334, 1336, 1338, 1340.

Alternatively, volumetric fluid flow rate through different openings1332 1334, 1336, 1338, 1340 can be calculated mathematically usingequations for modeling fluid flow through a tubular body. For example,volumetric flow rate of fluid passing through openings 1332 1334, 1336,1338, 1340 and into the drainage lumen 1224 can be calculated based on amass transfer shell balance evaluation, as described in detail below inconnection with the Mathematical Examples and FIGS. 15A-15C. Steps forderiving mass balance equations and for calculating a flow distributionbetween or volumetric flow rates for the openings 1332 1334, 1336, 1338,1340 are also described in detail below in connection with FIGS.15A-15C.

Another exemplary retention portion 2230 with openings 2332, 2334, 2336,2338, 2340 is illustrated in FIG. 12. As shown in FIG. 12, the retentionportion 2230 comprises numerous smaller perforations or openings 2332,2334, 2336, 2338, 2340. Each of the openings 2332, 2334, 2336, 2338,2340 can have a substantially identical cross-sectional area or one ormore openings 2332, 2334, 2336, 2338, 2340 can have differentcross-sectional areas. As shown in FIG. 12, the retention portion 2330comprises six sections 2310, 2312, 2314, 2316, 2318, 2320, such as aredescribed above, wherein each section comprises a plurality of theopenings 2332, 2334, 2336, 2338, 2340. In the example shown in FIG. 12,a number of openings 2332, 2334, 2336, 2338, 2340 per section increasestowards the distal end 2220 of the tube 2222, such that a total area ofopenings 1332 in each section increases compared to a proximallyadjacent section.

As shown in FIG. 12, openings 2332 of the first section 2310 arearranged along a first virtual line V1, which is substantially parallelto a central axis X1 of the retention portion 2230. Openings 2334, 2336,2338, 2340 of the second 2312, third 2314, fourth 2316, and fifth 2318sections, respectively, are positioned on the sidewall of the tube 2222in a gradually increasing number of rows, such that openings 2334, 2336,2338, 2340 of these sections also line up around a circumference of thetube 2222. For example, some of the openings 2334 of the second section2312 are positioned such that a second virtual line V2 extending arounda circumference of the sidewall of the tube 2222 contacts at least aportion of multiple openings 2334. For example, the second section 2312can comprise two or more rows of perforations or openings 2334, in whicheach opening 2334 has an equal or different cross-sectional area.Further, in some examples, at least one of the rows of the secondsection 2312 can be aligned along a third virtual line V3, which isparallel with the central axis X1 of the tube 2222, but is notco-extensive with the first virtual line V1. In a similar manner, thethird section 2314 can comprise five rows of perforations or openings2336, in which each opening 2336 has an equal or differentcross-sectional area; the fourth section 2316 can comprise seven rows ofperforations or openings 2338; and the fifth section 2318 can comprisenine rows of perforations or openings 2340. As in previous examples, thesixth section 2320 comprises a single opening, namely the open distalend 2220 of the tube 2222. In the example of FIG. 12, each of theopenings has the same area, although the area of one or more openingscan be different if desired.

Another exemplary retention portion 3230 with openings 3332, 3334, 3336,3338, 3340 is illustrated in FIG. 13. The retention portion 3230 of FIG.13 includes a plurality of similarly sized perforations or openings3332, 3334, 3336, 3338, 3340. As in previous examples, the retentionportion 3230 can be divided into six sections 3310, 3312, 3314, 3316,3318, 3320, each of which comprises at least one opening. Theproximal-most or first section 3310 includes one opening 3332. Thesecond section 3312 includes two openings 3334 aligned along the virtualline V2 extending around a circumference of the sidewall of the tube3222. The third section 3314 comprises a grouping of three openings3336, positioned at vertices of a virtual triangle. The fourth section3316 comprises a grouping of four openings 3338 positioned at corners ofa virtual square. The fifth section 3318 comprises ten openings 3340positioned to form a diamond shape on the sidewall of the tube 3222. Asin previous examples, the sixth section 3320 comprises a single opening,namely the open distal end 3220 of the tube 3222. The area of eachopening can range from about 0.001 mm² and about 2.5 mm². In the exampleof FIG. 13, each of the openings has the same area, although the area ofone or more openings can be different if desired.

Another exemplary retention portion 4230 with openings 4332, 4334, 4336,4338, 4340 is illustrated in FIG. 14. The openings 4332 4334, 4336,4338, 4340 of the retention portion 4330 have different shapes andsizes. For example, the first section 4310 includes a single circularopening 4332. The second section 4312 has a circular opening 4334 with alarger cross sectional area than the opening 4332 of the first section4310. The third section 4314 comprises three triangular shaped openings4336. The fourth section 4316 comprises a large circular opening 4338.The fifth section 4318 comprises a diamond shaped opening 4340. As inprevious examples, the sixth section 4320 comprises the open distal end4220 of the tube 4222. FIG. 14 illustrates one example of an arrangementof different shapes of openings in each section. It is understood thatthe shape of each opening in each section can be independently selected,for example the first section 4310 can have one or more diamond-shapedopenings or other shapes. The area of each opening can be the same ordifferent and can range from about 0.001 mm² and about 2.5 mm².

EXAMPLES

Calculation of Volumetric Flow Rate and Percentage of Flow Distribution

Having described various arrangements of openings for retention portionsof the ureteral catheter 1212, a method for determining the CalculatedPercentage of Flow Distribution and Calculated Volumetric Flow Ratethrough the catheter will now be described in detail. A schematicdrawing of an exemplary catheter with sidewall openings showing aposition of portions of the tube or drainage lumen used in the followingcalculations is shown in FIG. 16. Calculated Percentage of FlowDistribution refers to a percentage of total fluid flowing throughproximal portions of the drainage lumen which entered the drainage lumenthrough different openings or sections of the retention portion.Calculated Volumetric Flow rate refers to fluid flow per unit timethrough different portions of the drainage lumen or openings of theretention portion. For example, a volumetric flow rate for a proximalportion of the drainage lumen describes a rate of flow for a totalamount of fluid passing through the catheter. A volumetric flow rate foran opening refers to a volume of fluid which passes through the openingand into the drainage lumen per unit time. In Tables 3-5 below flow isdescribed as a percentage of total fluid flow or of a total volumetricflow rate for a proximal portion of the drainage lumen. For example, anopening having a flow distribution of 100% means that all fluid enteringthe drainage lumen passed through the opening. An opening having adistribution of 0% would indicate that none of the fluid in the drainagelumen entered the drainage lumen through that opening.

These volumetric flow rate calculations were used to determine and modelfluid flow through the retention portion 1230 of the ureter catheter1212 shown in FIGS. 7A and 10-10E. Further, these calculations show thatadjusting the area of openings and linear distribution of openings alongthe retention portion effects a distribution of fluid flow throughdifferent openings. For example, reducing the area of the proximal-mostopening decreases the proportion of fluid drawn into the catheterthrough the proximal most opening and increases the proportion of fluiddrawn into more distal openings of the retention portion.

For the following calculations, a tube length of 86 cm having an innerdiameter of 0.97 mm and an end hole inner diameter of 0.97 mm was used.Density of urine was 1.03 g/mL and had a coefficient of friction μ of8.02×10−3 Pa·S (8.02×10−3 kg/s·m) at 37° C. The urine volumetric flowrate passing through the catheter was 2.7 ml per minute (Q_(Total)) asdetermined by experimental measurement.

Calculated Volumetric Flow Rate is determined by a volumetric massbalance equation in which a sum total of volumetric flow through allperforations or openings 1232 of the five sections of the retentionportion (referred to herein as volumetric flow Q₂ to Q₆) and through theopen distal end 1220 (referred to herein as volumetric flow Q₁) equalsthe total volumetric flow (Q_(Total)) exiting the proximal end of thetube 1222 at a distance of 10 cm to 60 cm away from the last proximalopening, as shown in Equation 2.Q _(Total) =Q ₁ +Q ₂ +Q ₃ +Q ₄ +Q ₅ +Q ₆  (Equation 2)

A Modified Loss Coefficient (K′) for each of the sections is based onthree types of loss coefficients within the catheter model, namely: anInlet Loss Coefficient taking into account a pressure loss resulting ata pipe inlet (e.g., the openings and open distal end of the tube 1222);a Friction Loss Coefficient which takes into account pressure lossresulting from friction between the fluid and pipe wall; and a FlowJunction Loss Coefficient taking into account pressure loss resultingfrom the interaction of two flows coming together.

The Inlet Loss Coefficient is dependent on a shape of the orifice oropening. For example, a tapered or nozzle shaped orifice would increaseflow rate into the drainage lumen 1224. In a similar manner, asharp-edged orifice would have different flow properties than an orificewith less defined edges. For purposes of the following calculations, itis assumed that the openings 1232 are side orifice openings and the opendistal end 1220 of the tube 1222 is a sharp-edged opening. The crosssectional area of each opening is considered constant through the tubesidewall.

The Friction Loss Coefficient approximates pressure loss resulting fromfriction between the fluid and the adjacent inner wall of the tube 1222.Friction loss is defined according to the following equations:

$\begin{matrix}{{Re} = \frac{\rho\;{UD}}{\mu}} & \left( {{Equation}\mspace{14mu} 3.1} \right) \\{f = \frac{C_{f}}{Re}} & \left( {{Equation}\mspace{14mu} 3.2} \right) \\{K_{1\text{-}2} = {K_{2\text{-}3} = {K_{3\text{-}3} = {K_{4\text{-}3} = {K_{5\text{-}3} = {K_{f} = {f\frac{L}{D}}}}}}}} & \left( {{Equation}\mspace{14mu} 3.3} \right)\end{matrix}$

The Flow Junction Loss Coefficients are derived from loss coefficientsfor combining flow at a branch angle of 90 degrees. Values for the losscoefficients were obtained from Charts 13.10 and 13.11 of Miller D S,Internal Flow Systems, 1990, incorporated by reference herein. Thecharts use the ratio of the inlet orifice area (referred to as A1 in thecharts) to the pipe cross-sectional area (referred to as A3 in thecharts) and the ratio of the inlet orifice volumetric flow rate (Q1 inthe charts) to the resulting combined pipe volumetric flow rate (Q3 inthe charts). For example, for an area ratio of 0.6 between an area ofthe opening and an area of the drainage lumen, the following FlowJunction Loss Coefficients (K₁₃ and K₂₃) would be used.

Flow Ratio (Q₁/Q₃) 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 K₁₃ −0.58−0.04 0.11 0.45 0.75 1.13 1.48 1.81 2.16 2.56 K₂₃ 0.15 0.27 0.39 0.480.56 0.63 0.69 0.72 0.74 0.76

To calculate the Total Manifold Loss Coefficient (K), it is necessary toseparate the model into so-called “reference stations” and progressivelywork through and balance the pressure and flow distributions of the twopaths (e.g., flow through the opening and flow through the drainagelumen of the tube) to reach each station starting from the distal tip tothe most proximal “Station”. A graphical representation of the differentstations used for this calculation is shown in FIG. 16. For example, amost-distal “Station” A is the distal open end 1220 of the tube 122. Asecond Station A′ is the distal most opening on the sidewall of the tube122 (e.g., the opening(s) of the fifth section 1318 in FIGS. 11-14). Thenext station B is for flow through the drainage lumen 1224 just proximalto the A′ opening.

To calculate loss between Station A (the distal opening) and Station Bfor fluid entering through the open distal end of the tube 1222 (Path1), the modified loss coefficient (K′) is equal to:

$\begin{matrix}{K^{\prime} = {{{Inlet}\mspace{14mu}{Loss}} + {{Friction}\mspace{14mu}{Loss}} + {{Flow}\mspace{14mu}{Junction}\mspace{14mu}{Loss}}}} & \left( {{Equation}\mspace{14mu} 4.1} \right) \\{K_{B}^{\prime} = {{K_{1\text{-}1} \times \left( {\frac{A_{Pipe}}{A_{1}} \times Q_{1}} \right)^{2}} + {K_{1\text{-}2} \times Q_{1}^{2}} + {K_{1\text{-}3} \times \left( {Q_{1} + Q_{2}} \right)^{2}}}} & \left( {{Equation}\mspace{14mu} 4.2} \right)\end{matrix}$

In a similar manner, a second path to Station B is through theopening(s) 1334 of the fifth section 1318 (shown in FIGS. 11-14) of theretention portion 1330. A modified loss calculation for Path 2 iscalculated as follows:

$\begin{matrix}{K^{\prime} = {{{Inlet}\mspace{14mu}{Loss}} + {{Flow}\mspace{14mu}{Junction}\mspace{14mu}{Loss}}}} & \left( {{Equation}\mspace{14mu} 5.1} \right) \\{K_{B}^{\prime} = {{K_{2\text{-}1} \times \left( {\frac{A_{Pipe}}{A_{2}} \times Q_{2}} \right)^{2}} + {K_{2\text{-}2} \times \left( {Q_{1} + Q_{2}} \right)^{2}}}} & \left( {{Equation}\mspace{14mu} 5.2} \right)\end{matrix}$

The modified loss coefficients of both Path 1 and Path 2 must equate toensure the volumetric flow rates (Q₁ and Q₂) reflect the balanceddistribution within the manifold at Station B. The volumetric flow ratesare adjusted until equal modified loss coefficients for both paths isachieved. The volumetric flow rates can be adjusted because theyrepresent a fractional portion of a total volumetric flow rate(Q′_(Total)), which is assumed to be unity for the purpose of thisstep-by-step solution. Upon equating the two modified loss coefficients,one can then proceed to equating the two paths to reach station C (thefourth section 1316 in FIGS. 11-14).

Loss coefficients between Station B (flow through drainage lumen in thefifth section 1318) and Station C (flow through lumen in the fourthsection 1316) are calculated in a similar manner as shown by Equations5.1 and 5.2). For example, for Path 1 (Station B to Station C), themodified loss coefficient (K′) for the opening(s) of the fourth section1316 is defined as:K′=Loss to Station B+Friction Loss+Flow Junction Loss  (Equation 6.1)K′ _(C) =K′ _(B) +K ₂₋₃×(Q ₁ +Q ₂)² +K ₂₋₄×(Q ₁ +Q ₂ +Q ₃)²  (Equation6.2)

For Path 2 (Station B to C), the modified loss coefficient (K′) based onthe flow area of the opening(s) of the fourth section 1316 are definedas:

$\begin{matrix}{K^{\prime} = {{{Inlet}\mspace{14mu}{Loss}} + {{Flow}\mspace{14mu}{Junction}\mspace{14mu}{Loss}}}} & \left( {{Equation}\mspace{14mu} 7.1} \right) \\{K_{C}^{\prime} = {{K_{3\text{-}1} \times \left( {\frac{A_{Pipe}}{A_{3}} \times Q_{3}} \right)^{2}} + {K_{3\text{-}2} \times \left( {Q_{1} + Q_{2} + Q_{3}} \right)^{2}}}} & \left( {{Equation}\mspace{14mu} 7.2} \right)\end{matrix}$

As with the previous stations, the modified loss coefficients of bothPath 1 and Path 2 must equate to ensure the volumetric flow rates (Q₁,Q₂, and Q₃) reflect the balanced distribution within the manifold up toStation C. Upon equating the two modified loss coefficients, one canthen proceed to equating the two paths to reach Station D, Station E andStation F. The step-by-step solution process proceeds through eachstation as demonstrated until calculating the modified loss coefficientfor the final station, Station F in this case. The Total LossCoefficient (K) for the manifold can then be calculated using an actualQ_(Total) (volumetric flow rate through a proximal portion of thedrainage lumen) determined through experimental measurement.

$\begin{matrix}{K = \frac{K_{F}^{\prime}}{Q_{Total}}} & \left( {{Equation}\mspace{14mu} 8} \right)\end{matrix}$

The fractional volumetric flow rates calculated through the step-by-stepexercise can then be multiplied by the actual total volumetric flow rate(Q_(Total)) to determine the flow through each opening 1232 (shown inFIGS. 10-10E) and open distal end 1220.

EXAMPLES

Examples are provided below and shown in Tables 3-5 and FIGS. 15A-15Cfor the calculated volumetric flow rates.

Example 1

Example 1 illustrates a distribution of fluid flow for a retentionmember tube with different sized openings, which corresponds to theembodiment of the retention member 1330 shown in FIG. 11. As shown inTable 3, the proximal most opening (Q6) had a diameter of 0.48 mm, thedistal-most opening (Q5) on the sidewall of the tube had a diameter of0.88 mm, and the open distal end (Q6) of the tube had a diameter of 0.97mm. Each of the openings was circular.

The Percentage of Flow Distribution and Calculated Volumetric Flow Ratewere determined as follows.

Path to Station B Through Distal End of Tube (Path 1)

f 8.4 = C_(f)/Re (C_(f) = 64 for circular cross-section) K_(INLET) 0.16(Contraction coefficient. for sharp edged orifice entering pipe)K_(ORIFICE) 2.8 (Contraction coefficient. for sharp edged orifice w/ nooutlet pipe) K_(FRICTION) = f * (L/D) (Dependent on the length betweenorifices) Part 1-1 = Inlet loss coef × (A_(T)/A₁ × Q′₁)² Part 1-2 =Catheter friction loss × Q′₁ ² Part 1-3 = Through flow junction loss tostation 2 × (Q′₁ + Q′₂)² A₂/A_(T) = 0.82 Q′₂/(Q′₁ + 0.83 Q′₂) = K₁₋₃ =0.61 (From Miller, see table above) Part 1-1 = 0.0000 Part 1-2 = 0.0376Part 1-3 = 0.0065 K′ = 0.0442Path to Station B Through Sidewall Opening (Path 2)

Part 2-1 = Orifice loss coef × (A_(T)/A₂ × Q′₂)² Part 2-2 = Branch flowjunction loss to station 2 × (Q′₁ + Q′₂)² A₂/A_(T) = 0.82 Q′₂/(Q′₁ +Q′₂) = 0.83 K₂₋₂ = 1.3 (From Chart 13.10 of Miller) Part 2-1 = 0.0306Part 2-2 = 0.0138 K′ = 0.0444Path to Station C from Station B (Path 1+Path 2)

Part 2-3 = Catheter friction loss × (Q′₁ + Q′₂)² Part 2-4 = Through flowjunction loss to station 3 × (Q′₁ + Q′₂ + Q′₃)² A₃/A_(T) = 0.61Q′₃/(Q′₁ + Q′₂ + Q′₃) = 0.76 K₂₋₄ = 0.71 (From Chart 13.11 of Miller)Loss coefficient to 0.044 Station 2 = Part 2-3 = 0.921 Part 2-4 = 0.130K′ = 1.095Path to Station C Through Sidewall Opening (Path 3)

Part 3-1 = Orifice loss coef × (A_(T)/A₃ × Q′₃)² Part 3-2 = Branch flowjunction loss to station 3 × (Q′₁ + Q′₂ + Q′₃)² A₃/A_(T) = 0.61Q′₃/(Q′₁ + Q′₂ + Q′₃) = 0.76 K₃₋₂ = 1.7 (From Chart 13.10 of Miller)Part 3-1 = 0.785 Part 3-2 = 0.311 K′ = 1.096Path to Station D from Station C (Path 1+Path 2+Path 3)

Part 3-3 = Catheter friction loss × (Q′₁ + Q′₂ + Q′₃)² Part 3-4 =Through flow junction loss to station 4 × (Q′₁ + Q′₂ + Q′₃ + Q′₄)²A₄/A_(T) = 0.46 Q′₄/(Q′₁ + Q′₂ + Q′₃ + Q′₄) = 0.70 K₃₋₄ = 0.77 (FromChart 13.11 of Miller) Loss coefficient to Station 3 = 1.10 Part 3-3 =15.90 Part 3-4 = 1.62 K′ = 18.62Path to Station D Through Sidewall Opening (Path 4)

Part 4-1 = Orifice loss coef × (A_(T)/A₄ × Q′₄)² Part 4-2 = Branch flowjunction loss to station 4 × (Q′₁ + Q′₂ + Q′₃ + Q′₄)² A₄/A_(T) = 0.46Q′₄/(Q′₁ + Q′₂ + Q′₃ + Q′₄) = 0.70 K₄₋₂ = 2.4 (From Chart 13.10 ofMiller) Part 4-1 = 13.59 Part 4-2 = 5.04 K′ = 18.62Path to Station E from Station D (Path 1+Path 2+Path 3+Path 4)

Part 4-3 = Catheter friction loss × (Q′₁ + Q′₂ + Q′₃ + Q′₄)² Part 4-4 =Through flow junction loss to station 5 × (Q′₁ + Q′₂ + Q′₃ + Q′₄ + Q′₅)²A₅/A_(T) = 0.36 Q′₅/(Q′₁ + Q′₂ + Q′₃ + Q′₄ + Q′₅) = 0.65 K₃₋₄ = 0.78(From Chart 13.11 of Miller) Loss coefficient to Station 4 = 18.6 Part4-3 = 182.3 Part 4-4 = 13.3 K′ = 214.2Path to Station E Through Sidewall Opening (Path 5)

Part 5-1 = Orifice loss coef × (A_(T)/A₅ × Q′₅)² Part 5-2 = Branch flowjunction loss to station 5 × (Q′₁ + Q′₂ + Q′₃ + Q′₄ + Q′₅)² A₅/A_(T) =0.36 Q′₅/(Q′₁ + Q′₂ + Q′₃ + Q′₄ + Q′₅) = 0.65 K₄₋₂ = 3.3 (From Chart13.10 of Miller) Part 5-1 = 157.8 Part 5-2 = 56.4 K′ = 214.2Path to Station F from Station E (Through Paths 1-5)

Part 5-3 = Catheter friction loss × (Q′₁ + Q′₂ + Q′₃ + Q′₄ + Q′₅)² Part5-4 = Through flow junction loss to station 6 × (Q′₁ + Q′₂ + Q′₃ + Q′₄ +Q′₅ + Q′₆)² A₆/A_(T) = 0.24 Q′₆/(Q′₁ + Q′₂ + Q′₃ + Q′₄ + 0.56 Q′₅ + Q′₆)= K₃₋₄ = 0.77 (From Chart 13.11 of Miller) Loss coefficient to Station 5= 214.2 Part 5-3 = 1482.9 Part 5-4 = 68.3 K′ = 1765.4Path to Station F Through Sidewall Opening (Path 6)

Part 6-1 = Orifice loss coef × (A_(T)/A₆ × Q′₆)² Part 6-2 = Branch flowjunction loss to station 6 × (Q′₁ + Q′₂ + Q′₃ + Q′₄ + Q′₅ + Q′₆)²A₆/A_(T) = 0.24 Q′₆/(Q′₁ + Q′₂ + Q′₃ + Q′₄ + 0.56 Q′₅ + Q′₆) = K₄₋₂ =5.2 (From Chart 13.10 of Miller) Part 6-1 = 1304.3 Part 6-2 = 461.2 K′ =1765.5

In order to calculate flow distribution for each “Station” or opening,the calculated K′ values were multiplied by actual total volumetric flowrate (Q_(Total)) to determine the flow through each perforation anddistal end hole. Alternatively, calculated results could be presented asa percentage of total flow or a flow distribution as shown in Table 3.As shown in Table 3 and in FIG. 15C, the Percentage of Flow Distribution(% Flow Distribution) through the proximal most opening (Q6) was 56.1%.Flow through the two proximal-most openings (Q6 and Q5) was 84.6%.

TABLE 3 Cumulative % Flow Diameter Length Length Position Distribution(mm) (mm) (mm) Q₆′ 56.1% 0.48 0 0 (proximal) Q₅′ 28.5% 0.58 10 10 Q₄′10.8% 0.66 10 20 Q₃′  3.5% 0.76 10 30 Q₂′  0.9% 0.88 10 40 Q₁′ (distal) 0.2% 0.97 15 55 Q_(TOTAL)  100%

As demonstrated in Example 1, the increasing diameters of perforationsgoing from the proximal to distal regions of the retention portion ofthe tube results in more evenly distributed flow across the entireretention portion.

Example 2

In Example 2, each opening has the same diameter and area. As shown inTable 4 and FIG. 15A, in that case, flow distribution through theproximal-most opening is 86.2% of total flow through the tube. Flowdistribution through the second opening is 11.9%. Therefore, in thisexample, it was calculated that 98.1% of fluid passing through thedrainage lumen entered the lumen through the two proximal-most openings.Compared to Example 1, Example 2 has increased flow through the proximalend of the tube. Therefore, Example 1 provides a wider flow distributionin which a greater percentage of fluid enters the drainage lumen throughopenings other than the proximal-most opening. As such, fluid can bemore efficiently collected through multiple openings reducing fluidbackup and improving distribution of negative pressure through the renalpelvis and/or kidneys.

TABLE 4 Cumulative % Flow Diameter Length Length Position Distribution(mm) (mm) (mm) Q₆′ 86.2% 0.88 0 0 (proximal) Q₅′ 11.9% 0.88 22 22 Q₄′ 1.6% 0.88 22 44 Q₃′  0.2% 0.88 22 66 Q₂′ 0.03% 0.88 22 88 Q₁′ (distal)0.01% 0.97 22 110 Q_(TOTAL)  100%

Example 3

Example 2 also illustrates flow distribution for openings having thesame diameter. However, as shown in Table 5, the openings are closertogether (10 mm vs. 22 mm). As shown in Table 5 and FIG. 15B, 80.9% offluid passing through the drainage lumen entered the drainage lumenthrough the proximal most opening (Q6). 96.3% of fluid in the drainagelumen entered the drainage lumen through the two proximal-most openings(Q5 and Q6).

TABLE 5 % Flow Cumulative Position Distribution Diameter (mm) Length(mm) Length (mm) Q₆′ 80.9% 0.88 0 0 (proximal) Q₅′ 15.4% 0.88 10 10 Q₄′ 2.9% 0.88 10 20 Q₃′  0.6% 0.88 10 30 Q₂′  0.1% 0.88 10 40 Q₁′ (distal)0.02% 0.97 15 55 Q_(TOTAL)  100%

Referring generally now to FIGS. 17-41C, and more specifically to FIG.17, there are shown two exemplary ureteral catheters 5000, 5001positioned within the urinary tract of a patient, and a bladder catheter116. The ureteral catheter 5000, 5001 comprises: a drainage lumen 5002,5003 for draining fluid such as urine from at least one of a patient'skidney 2, 4, renal pelvis 20, 21 or in the ureter 6, 8 adjacent to therenal pelvis 20, 21. The drainage lumen 5002, 5003 comprises a distalportion 5004, 5005 configured to be positioned in a patient's kidney 2,4, renal pelvis 20, 21 and/or in the ureter 6, 8 adjacent to the renalpelvis 20, 21 and a proximal portion 5006, 5007 through which fluid 5008is drained to the bladder 10 or outside of the body of the patient, asshown in FIGS. 2B and 2C.

In some examples, the distal portion 5004, 5005 comprises an open distalend 5010, 5011 for drawing fluid into the drainage lumen 5002, 5003. Thedistal portion 5004, 5005 of the ureteral catheter 5000, 5001 furthercomprises a retention portion 5012, 5013 for maintaining the distalportion 5004, 5005 of the drainage lumen or tube 5002, 5003 in theureter and/or kidney. The retention portion 5012, 5013 can be flexibleand/or bendable to permit positioning of the retention portion 5012,5013 in the ureter, renal pelvis, and/or kidney. For example, theretention portion 5012, 5013 is desirably sufficiently bendable toabsorb forces exerted on the catheter 5000, 5001 and to prevent suchforces from being translated to the ureters. Further, if the retentionportion 5012, 5013 is pulled in the proximal direction P (shown in FIG.17) toward the patient's bladder 10, the retention portion 5012, 5013can be sufficiently flexible to begin to unwind, straightened orcollapsed so that it can be drawn through the ureter 6, 8.

In some examples, the retention portion comprises a funnel support.Non-limiting examples of different shapes of funnel supports are shownin FIGS. 7A, 7B, 17, and 18A-41C, which are discussed in detail below.Generally, the funnel support comprises at least one sidewall. The atleast one sidewall of the funnel support comprises a first diameter anda second diameter, the first diameter being less than the seconddiameter. The second diameter of the funnel support is closer to an endof the distal portion of the drainage lumen than the first diameter.

The proximal portion of the drainage lumen or drainage tube isessentially free of or free of openings. While not intending to be boundby any theory, it is believed that when negative pressure is applied atthe proximal end of the proximal portion of the drainage lumen, thatopenings in the proximal portion of the drainage lumen or drainage tubemay be undesirable as such openings may diminish the negative pressureat the distal portion of the ureteral catheter and thereby diminish thedraw or flow of fluid or urine from the kidney and renal pelvis of thekidney. It is desirable that the flow of fluid from the ureter and/orkidney is not prevented by occlusion of the ureter and/or kidney by thecatheter. Also, while not intending to be bound by any theory, it isbelieved that when negative pressure is applied at the proximal end ofthe proximal portion of the drainage lumen, ureter tissue may be drawnagainst or into openings along the proximal portion of the drainagelumen, which may irritate the tissues.

Some examples of ureteral catheters comprising a retention portioncomprising a funnel support according to the present invention are shownin FIGS. 7A, 7B, 17, and 18A-41C. In FIGS. 7A-10E, the funnel support isformed by a coil of tubing. In FIGS. 17-41C, other examples of thefunnel support are shown. Each of these funnel supports according to thepresent invention will be discussed in detail below.

Referring now to FIGS. 18A-D, in some examples, there is shown a distalportion 5004 of the ureteral catheter, indicated generally as 5000. Thedistal portion 5004 comprises a retention portion 5012 comprising afunnel-shaped support 5014. The funnel-shaped support 5014 comprises atleast one sidewall 5016. As shown in FIGS. 18C and 18D, the outerperiphery 1002 or protective surface area 1001 comprises the outersurface or outer wall 5022 of the funnel-shaped support 5014. The one ormore drainage holes, ports or perforations, or interior opening 5030,are disposed on the protected surface areas or inner surface areas 1000of the funnel-shaped support 5014. As shown in FIGS. 18C and 18D, thereis a single drainage hole 5030 at the base portion 5024 of thefunnel-shaped support, although multiple holes can be present.

The at least one sidewall 5016 of the funnel support 5014 comprises afirst (outer) diameter D4 and a second (outer) diameter D5, the firstouter diameter D4 being less than the second outer diameter D5. Thesecond outer diameter D5 of the funnel support 5014 is closer to thedistal end 5010 of the distal portion 5004 of the drainage lumen 5002than is the first outer diameter D4. In some examples the first outerdiameter D4 can range from about 0.33 mm to 4 mm (about 1 Fr to about 12Fr (French catheter scale)), or about 2.0±0.1 mm. In some examples, thesecond outer diameter D5 is greater than first outer diameter D4 and canrange from about 1 mm to about 60 mm, or about 10 mm to 30 mm, or about18 mm±2 mm.

In some examples, the at least one sidewall 5016 of the funnel support5014 can further comprise a third diameter D7 (shown in FIG. 18B), thethird diameter D7 being less than the second outer diameter D5. Thethird diameter D7 of the funnel support 5014 is closer to the distal end5010 of the distal portion 5004 of the drainage lumen 5002 than is thesecond diameter D5. The third diameter D7 is discussed in greater detailbelow regarding the lip. In some examples, the third diameter D7 canrange from about 0.99 mm to about 59 mm, or about 5 mm to about 25 mm.

The at least one sidewall 5016 of the funnel support 5014 comprises afirst (inner) diameter D6. The first inner diameter D6 is closer to theproximal end 5017 of the funnel support 5014 than is the third diameterD7. The first inner diameter D6 is less than the third diameter D7. Insome examples the first inner diameter D6 can range from about 0.05 mmto 3.9 mm, or about 1.25±0.75 mm.

In some examples, an overall height H5 of the sidewall 5016 along acentral axis 5018 of the retention portion 5012 can range from about 1mm to about 25 mm. In some examples, the height H5 of the sidewall canvary at different portions of the sidewall, for example if the sidewallhas an undulating edge or rounded edges such as is shown in FIG. 24. Insome examples, the undulation can range from about 0.01 mm to about 5 mmor more, if desired.

In some examples, as shown in FIGS. 7A-10E, and 17-41C, the funnelsupport 5014 can have a generally conical shape. In some examples, theangle 5020 between the outer wall 5022 near the proximal end 5017 of thefunnel support 5014 and the drainage lumen 5002 adjacent to the baseportion 5024 of the funnel support 5014 can range from about 100 degreesto about 180 degrees, or about 100 degrees to about 160 degrees, orabout 120 degrees to about 130 degrees. The angle 5020 may vary atdifferent positions about the circumference of the funnel support 5014,such as is shown in FIG. 22A, in which the angle 5020 ranges from about140 degrees to about 180 degrees.

In some examples, the edge or lip 5026 of the distal end 5010 of the atleast one sidewall 5016 can be rounded, square, or any shape desired.The shape defined by the edge 5026 can be, for example, circular (asshown in FIGS. 18C and 23B), elliptical (as shown in FIG. 22B), lobes(as shown in FIGS. 28B, 29B and 31), square, rectangular, or any shapedesired.

Referring now to FIGS. 28A-31, there is shown a funnel support 5300wherein the at least one sidewall 5302 comprises a plurality oflobe-shaped longitudinal folds 5304 along the length L7 of the sidewall5302. The outer periphery 1002 or protective surface area 1001 comprisesthe outer surface or outer wall 5032 of the funnel-shaped support 5300.The one or more drainage holes, ports or perforations, or interioropening, are disposed on the protected surface areas or inner surfaceareas 1000 of the funnel-shaped support 5300. As shown in FIG. 28B,there is a single drainage hole at the base portion of the funnel-shapedsupport, although multiple holes can be present.

The number of folds 5304 can range from 2 to about 20, or about 6, asshown. In this example, the folds 5304 can be formed from one or moreflexible materials, such as silicone, polymer, solid material, fabric,or a permeable mesh to provide the desired lobe shape. The folds 5304can have a generally rounded shape as shown in cross-sectional view 51B.The depth D100 of each fold 5304 at the distal end 5306 of the funnelsupport 5300 can be the same or vary, and can range from about 0.5 mm toabout 5 mm.

Referring now to FIGS. 29A and 29B, one or more folds 5304 can compriseat least one longitudinal support member 5308. The longitudinal supportmember(s) 5308 can span the entire length L7 or a portion of the lengthL7 of the funnel support 5300. The longitudinal support members 5308 canbe formed from a flexible yet partially rigid material, such as atemperature sensitive shape memory material, for example nitinol. Thethickness of the longitudinal support members 5308 can range from about0.01 mm to about 1 mm, as desired. In some examples, the nitinol framecan be covered with a suitable waterproof material such as silicon toform a tapered portion or funnel. In that case, fluid is permitted toflow down the inner surface 5310 of the funnel support 5300 and into thedrainage lumen 5312. In other examples, the folds 5304 are formed fromvarious rigid or partially rigid sheets or materials bended or molded toform a funnel-shaped retention portion.

Referring now to FIGS. 30 and 31, the distal end or edge 5400 of thefolds 5402 can comprise at least one edge support member 5404. The edgesupport member(s) 5404 can span the entire circumference 5406 or one ormore portions of the circumference 5406 of the distal edge 5400 of thefunnel support 5408. The edge support member(s) 5404 can be formed froma flexible yet partially rigid material, such as a temperature sensitiveshape memory material, for example nitinol. The thickness of the edgesupport member(s) 5404 can range from about 0.01 mm to about 1 mm, asdesired.

In some examples, such as are shown in FIGS. 18A-C, the distal end 5010of the drainage lumen 5002 (or funnel support 5014) can have an inwardlyfacing lip 5026 oriented towards the center of the funnel support 5014,for example of about 0.01 mm to about 1 mm, to inhibit irritating thekidney tissue. Thus, the funnel support 5014 can comprise a thirddiameter D7 less than the second diameter D5, the third diameter D7being closer to an end 5010 of the distal portion 5004 of the drainagelumen 5002 than the second diameter D5. The outer surface 5028 of thelip 5026 can be rounded, a square edge, or any shape desired. The lip5026 may assist in providing additional support to the renal pelvis andinternal kidney tissues.

Referring now to FIGS. 24A-C, in some examples, the edge 5200 of thedistal end 5202 of the at least one sidewall 5204 can be shaped. Forexample, the edge 5200 can comprise a plurality of generally roundededges 5206 or scallops, for example about 4 to about 20 or more roundededges. The rounded edges 5206 can provide more surface area than astraight edge to help support the tissue of the renal pelvis or kidneyand inhibit occlusion. The edge 5200 can have any shape desired, butpreferably is essentially free of or free of sharp edges to avoidinjuring tissue.

In some examples, such as are shown in FIGS. 18A-C and 22A-23B, thefunnel support 5014 comprises a base portion 5024 adjacent to the distalportion 5004 of the drainage lumen 5002. The base portion 5024 comprisesat least one interior opening 5030 aligned with an interior lumen 5032of the drainage lumen 5002 of the proximal portion 5006 of the drainagelumen 5002 for permitting fluid flow into the interior lumen 5032 of theproximal portion 5006 of the drainage lumen 5002. In some examples, thecross-section of the opening 5030 is circular, although the shape mayvary, such as ellipsoid, triangular, square, etc.

In some examples, such as is shown in FIGS. 22A-23B, a central axis 5018of the funnel support 5014 is offset with respect to a central axis 5034of the proximal portion 5006 of the drainage lumen 5002. The offsetdistance X from the central axis 5018 of the funnel support 5014 withrespect to the central axis 5034 of the proximal portion 5006 can rangefrom about 0.1 mm to about 5 mm.

The at least one interior opening 5030 of the base portion 5024 has adiameter D8 (shown, for example, in FIGS. 18C and 23B) ranging fromabout 0.05 mm to about 4 mm. In some examples, the diameter D8 of theinterior opening 5030 of the base portion 5024 is about equal to thefirst inner diameter D6 of the adjacent proximal portion 5006 of thedrainage lumen.

In some examples, the ratio of the height H5 of the at least onesidewall 5016 funnel support 5014 to the second outer diameter D5 of theat least one sidewall 5016 of the funnel support 5014 ranges from about1:25 to about 5:1.

In some examples, the at least one interior opening 5030 of the baseportion 5024 has a diameter D8 ranging from about 0.05 mm to about 4 mm,the height H5 of the at least one sidewall 5016 of the funnel support5014 ranges from about 1 mm to about 25 mm, and the second outerdiameter D5 of the funnel support 5014 ranges from about 5 mm to about25 mm.

In some embodiments, the thickness T1 (shown in FIG. 18B, for example)of the at least one sidewall 5016 of the funnel support 5014 can rangefrom about 0.01 mm to about 1.9 mm, or about 0.5 mm to about 1 mm. Thethickness T1 can be generally uniform throughout the at least onesidewall 5016, or it may vary as desired. For example, the thickness T1of the at least one sidewall 5016 can be less or greater near the distalend 5010 of the distal portion 5004 of the drainage lumen 5002 than atthe base portion 5024 of the funnel support 5014.

Referring now to FIGS. 18A-21, along the length of the at least onesidewall 5016, the sidewall 5016 can be straight (as shown in FIGS. 18Aand 20), convex (as shown in FIG. 19), concave (as shown in FIG. 21), orany combination thereof. As shown in FIGS. 19 and 21, the curvature ofthe sidewall 5016 can be approximated from the radius of curvature Rfrom the point Q such that a circle centered at Q meets the curve andhas the same slope and curvature as the curve. In some examples, theradius of curvature ranges from about 2 mm to about 12 mm. In someexamples, the funnel support 5014 has a generally hemispherical shape,as shown in FIG. 19.

In some examples, the at least one sidewall 5016 of the funnel support5014 is formed from a balloon 5100, for example as shown in FIGS. 35A,35 B, 38A and 38B. The balloon 5100 can have any shape that provides afunnel support to inhibit occlusion of the ureter, renal pelvis, and/orthe rest of the kidney. As shown in FIGS. 35A and 35B, the balloon 5100has the shape of a funnel. The balloon can be inflated after insertionor deflated before removal by adding or removing gas or air through thegas port(s) 5102. The gas port(s) 5102 can simply be contiguous with theinterior 5104 of the balloon 5100, e.g., the balloon 5100 can beadjacent to the interior 5106 or encase the exterior 5108 of an adjacentportion of the proximal portion 5006 of the drainage lumen 5002. Thediameter D9 of the sidewall 5110 of the balloon 5100 can range fromabout 1 mm to about 3 mm, and can vary along its length such that thesidewall has a uniform diameter, tapers toward the distal end 5112 ortapers toward the proximal end 5114 of the funnel support 5116. Theouter diameter D10 of the distal end 5112 of the funnel support 5116 canrange from about 5 mm to about 25 mm.

In some examples, the at least one sidewall 5016 of the funnel support5014 is continuous along the height H5 of the at least one sidewall5016, for example as shown in FIGS. 18A, 19, 20, and 21. In someexamples, the at least one sidewall 5016 of the funnel support 5014comprises a solid wall, for example the sidewall 5016 is not permeablethrough the sidewall after 24 hours of contact with a fluid such asurine on one side.

In some examples, the at least one sidewall of the funnel support isdiscontinuous along the height or the body of the at least one sidewall.As used herein, “discontinuous” means that the at least one sidewallcomprises at least one opening for permitting the flow of fluid or urinetherethrough into the drainage lumen, for example by gravity or negativepressure. In some examples, the opening can be a conventional openingthrough the sidewall, or openings within a mesh material, or openingswithin a permeable fabric. The cross-sectional shape of the opening canbe circular or non-circular, such as rectangular, square, triangular,polygonal, ellipsoid, as desired. In some examples, an “opening” is agap between adjacent coils in a retention portion of a cathetercomprising a coiled tube or conduit.

As used herein, “opening” or “hole” means a continuous void space orchannel through the sidewall from the outside to the inside of thesidewall, or vice versa. In some examples, each of the at least oneopening(s) can have an area which can be the same or different and canrange from about 0.002 mm² to about 100 mm², or about 0.002 mm² to about10 mm². As used herein, the “area” or “surface area” or “cross-sectionalarea” of an opening means the smallest or minimum planar area defined bya perimeter of the opening. For example, if the opening is circular andhas a diameter of about 0.36 mm (area of 0.1 mm²) at the outside of thesidewall, but a diameter of only 0.05 mm (area of 0.002 mm²) at somepoint within the sidewall or on the opposite side of the sidewall, thenthe “area” would be 0.002 mm² since that is the minimum or smallestplanar area for flow through the opening in the sidewall. If the openingis square or rectangular, the “area” would be the length times the widthof the planar area. For any other shapes, the “area” can be determinedby conventional mathematical calculations well known to those skilled inthe art. For example, the “area” of an irregular shaped opening is foundby fitting shapes to fill the planar area of the opening, calculatingthe area of each shape and adding together the area of each shape.

In some examples, at least a portion of the sidewall comprises at leastone (one or more) openings. Generally, the central axis of theopening(s) can be generally perpendicular to the planar outer surface ofthe sidewall, or the opening(s) can be angled with respect to the planarouter surface of the sidewalls. The dimensions of the bore of theopening may be uniform throughout its depth, or the width may vary alongthe depth, either increasing, decreasing, or alternating in widththrough the opening from the exterior surface of the sidewall to theinterior surface of the sidewall.

Referring now to FIGS. 9A-9E, 10A, 10E, 11-14, 27, 32A, 32B, 33 and 34,in some examples at least a portion of the sidewall comprises at leastone (one or more) openings. The opening(s) can be positioned anywherealong the sidewall. For example, the openings can be uniformlypositioned throughout the sidewall, or positioned in specified regionsof the sidewall, such as closer to the distal end of the sidewall orcloser to the proximal end of the sidewall, or in vertical or horizontalor random groupings along the length or circumference of the sidewall.While not intending to be bound by any theory, it is believed that, whennegative pressure is applied at the proximal end of the proximal portionof the drainage lumen, openings in the proximal portion of the funnelsupport that are directly adjacent to the ureter, renal pelvis and/orother kidney tissue may be undesirable as such openings may diminish thenegative pressure at the distal portion of the ureteral catheter andthereby diminish the draw or flow of fluid or urine from the kidney andrenal pelvis of the kidney, as well as perhaps irritate the tissue.

The number of openings can vary from 1 to 1000 or more, as desired. Forexample, in FIG. 27, six openings (three on each side) are shown. Asdiscussed above, in some examples, each of the at least one opening(s)can have an area which can be the same or different and can range fromabout 0.002 mm² to about 50 mm², or about 0.002 mm² to about 10 mm².

In some examples, as shown in FIG. 27, the openings 5500 can bepositioned closer the distal end 5502 of the sidewall 5504. In someexamples, the opening(s) are positioned in the distal half 5506 of thesidewall towards the distal end 5502. In some examples, the openings5500 are evenly distributed around the circumference of the distal half5506 or even closer to the distal end 5502 of the sidewall 5504.

In contrast, in FIG. 32B, the openings 5600 are positioned near theproximal end 5602 of an inner sidewall 5604, and do not directly contactthe tissue since there is an outer sidewall 5606 between the opening5600 and the tissue. Alternatively or additionally, one or moreopening(s) 5600 can be positioned near the distal end of the innersidewall, as desired. The inner sidewall 5604 and outer sidewall 5606can be connected by one or more supports 5608 or ridges connecting theoutside 5610 of the inner sidewall 5604 to the inside 5612 of the outersidewall 5606.

In some non-limiting examples, such as are shown in FIGS. 9A-9E, 10A,10D-10G, 18B, 18D, 18E, 20, 22A, 22B, 23A, 23B, 24A-24C, 25, 26, 27,28A, 28B, 29A-29C, 30, 31, 32A, 32B, 33, 34, 35A, 35B, 37B, 38A, 39B,39C, 40A-40C, and 41A-41C, a protected surface area(s) or inner surfacearea(s) 1000 can be established by a variety of different shapes ormaterials. Non-limiting examples of protected surface areas or innersurface areas 1000 can comprise, for example, the interior portions 152,5028, 5118, 5310, 5410, 5510, 5616, 5710, 5814, 6004 of a funnel 150,5014, 5116, 5300, 5408, 5508, 5614, 5702, 5802, 6000, the interiorportions 164, 166, 168, 170, 338, 1281, 1283, 1285 of a coil 183, 184,185, 187, 334, 1280, 1282, 1284, the interior portions 5902, 6003 of aporous material 5900, 6002, the interior portions 162, 5710, 5814 of amesh 57, 5704, 5804, or the interior portions 536 of a cage 530 withprotected drainage holes 533.

In some non-limiting examples, one or more protected drainage holes,ports or perforations 133, 1233 are disposed on the protected surfacearea 1000. Upon application of negative pressure therapy through thecatheter, the urothelial or mucosal tissue 1003, 1004 conforms orcollapses onto the outer periphery 189, 1002 or protective surface area1001 of the retention portion 130, 330, 410, 500, 1230, 1330, 2230,3230, 4230, 5012, 5013 of the catheter and is thereby prevented orinhibited from occluding one or more of the protected drainage holes,ports or perforations 133, 1233 disposed on the protected surface areaor inner surface area 1000, and thereby a patent fluid column or flow isestablished, maintained, or enhanced between the renal pelvis andcalyces and the drainage lumen 124, 324, 424, 524, 1224, 5002, 5003,5312, 5708, 5808.

In some examples, the retention portion 130, 330, 410, 500, 1230, 1330,2230, 3230, 4230, 5012, 5013 comprises one or more helical coils havingoutwardly facing sides 1288 and inwardly facing sides 1286, and whereinthe outer periphery 1002 or protective surface area 1001 comprises theoutwardly facing sides 1288 of the one or more helical coils, and theone or more protected drainage holes, ports or perforations 133, 1233are disposed on the inwardly facing sides 1286 (protected surface areaor inner surface area 1000) of the one or more helical coils.

For example, a funnel shape, as shown in FIG. 25, can create a sidewall5700 that conforms to the natural anatomical shape of the renal pelvispreventing the urothelium from constricting the fluid column. Theinterior 5710 of the funnel support 5702 provides a protected surfacearea 1000 having openings 5706 therethrough which provide a passagewaythrough which a fluid column can flow from the calyces into the drainagelumen 5708. Similarly, the mesh form of FIG. 26 can also create aprotected surface area 1000, such as interior 5814 of the mesh 5804,between the calyces and the drainage lumen 5808 of the catheter. Themesh 5704, 5804 comprises a plurality of openings 5706, 5806therethrough for permitting fluid flow into the drainage lumen 5708,5808. In some examples, the maximum area of an opening can be less thanabout 100 mm², or less than about 1 mm², or about 0.002 mm² to about 1mm², or about 0.002 mm² to about 0.05 mm². The mesh 5704, 5804 can beformed from any suitable metallic or polymeric material such as arediscussed above.

In some examples, the funnel support further comprises a cover portionover the distal end of the funnel support. This cover portion can beformed as an integral part of the funnel support or connected to thedistal end of the funnel support. For example, as shown in FIG. 26, thefunnel support 5802 comprises a cover portion 5810 across the distal end5812 of the funnel support 5802 and projecting from the distal end 5812of the funnel support 5802. The cover portion 5810 can have any shapedesired, such as flat, convex, concave, undulating, and combinationsthereof. The cover portion 5810 can be formed from mesh or any polymericsolid material as discussed above. The cover portion 5810 can provide anouter periphery 1002 or protective surface area 1001 to assist insupporting the pliant tissue in the kidney region to facilitate urineproduction.

In some examples, the funnel support comprises a porous material, forexample as shown in FIGS. 39A-40C. FIGS. 39A-40C and suitable porousmaterials are discussed in detail below. Briefly, in FIGS. 39 and 40,the porous material itself is the funnel support. In FIG. 39, the funnelsupport is a wedge of porous material. In FIG. 40, the porous materialis in the shape of a funnel. In some examples, such as FIG. 33, theporous material 5900 is positioned within the interior 5902 of thesidewall 5904. In some examples, such as FIG. 34, the funnel support6000 comprises a porous liner 6002 positioned adjacent to the interior6004 of the sidewall 6006. The thickness T2 of the porous liner 6002 canrange from about 0.5 mm to about 12.5 mm, for example. The area of theopenings within the porous material can be about 0.002 mm² to about 100mm², or less.

Referring now to FIGS. 37A and 37B, for example, a retention portion 130of a ureteral catheter 112 comprises a catheter tube 122 having awidened and/or tapered distal end portion which, in some examples, isconfigured to be positioned in the patient's renal pelvis and/or kidney.For example, the retention portion 130 can be a funnel-shaped structurecomprising an outer surface 185 configured to be positioned against theureter and/or kidney wall and comprising an inner surface 186 configuredto direct fluid toward a drainage lumen 124 of the catheter 112. Theretention portion can be configured into a funnel-shaped support havingan outer surface 185 and an inner surface 186, and wherein the outerperiphery 189 or protective surface area 1001 comprises the outersurface 185 of the funnel-shaped support, and the one or more drainageholes, ports or perforations 133, 1233 are disposed on the inner surface186 at the base of the funnel-shaped support. In another example shownin FIGS. 32A and 32B, the retention portion can be configured into afunnel-shaped support 5614 having an outer surface and an inner surface5616, and wherein the outer periphery 1002 or protective surface area1001 comprises the outer surface of the outer sidewall 5606. Theprotected surface area 1000 can comprise the inner sidewall 5604 of theinner funnel and the one or more drainage holes, ports or perforations5600 can be disposed on the inner sidewall 5604 of the funnel-shapedsupport.

Referring to FIGS. 37A and 37B, the retention portion 130 can comprise aproximal end 188 adjacent to the distal end of the drainage lumen 124and having a first diameter D1 and a distal end 190 having a seconddiameter D2 that is greater than the first diameter D1 when theretention portion 130 is in its deployed position. In some examples, theretention portion 130 is transitionable from a collapsed or compressedposition to the deployed position. For example, the retention portion130 can be biased radially outward such that when the retention portion130 is advanced to its fluid collecting position, the retention portion130 (e.g., the funnel portion) expands radially outward to the deployedstate.

The retention portion 130 of the ureteral catheter 112 can be made froma variety of suitable materials that are capable of transitioning fromthe collapsed state to the deployed state. In one example, the retentionportion 130 comprises a framework of tines or elongated members formedfrom a temperature sensitive shape memory material, such as nitinol. Insome examples, the nitinol frame can be covered with a suitablewaterproof material such as silicon to form a tapered portion or funnel.In that case, fluid is permitted to flow down the inner surface 186 ofthe retention portion 130 and into the drainage lumen 124. In otherexamples, the retention portion 130 is formed from various rigid orpartially rigid sheets or materials bended or molded to form afunnel-shaped retention portion as illustrated in FIGS. 37A and 37B.

In some examples, the retention portion of the ureteral catheter 112 caninclude one or more mechanical stimulation devices 191 for providingstimulation to nerves and muscle fibers in adjacent tissues of theureter(s) and renal pelvis. For example, the mechanical stimulationdevices 191 can include linear or annular actuators embedded in ormounted adjacent to portions of the sidewall of the catheter tube 122and configured to emit low levels of vibration. In some examples,mechanical stimulation can be provided to portions of the ureters and/orrenal pelvis to supplement or modify therapeutic effects obtained byapplication of negative pressure. While not intending to be bound bytheory, it is believed that such stimulation affects adjacent tissuesby, for example, stimulating nerves and/or actuating peristaltic musclesassociated with the ureter(s) and/or renal pelvis. Stimulation of nervesand activation of muscles may produce changes in pressure gradients orpressure levels in surrounding tissues and organs which may contributeto or, in some cases, enhance therapeutic benefits of negative pressuretherapy.

With reference to FIGS. 38A and 38B, according to another example, aretention portion 330 of a ureteral catheter 312 comprises a cathetertube 322 having a distal portion 318 formed in a helical structure 332and an inflatable element or balloon 350 positioned proximal to thehelical structure 332 to provide an additional degree of retention inthe renal pelvis and/or fluid collection location. A balloon 350 can beinflated to pressure sufficient to retain the balloon in the renalpelvis or ureter, but low enough to avoid distending or damaging thesestructures. Suitable inflation pressures are known to those skilled inthe art and are readily discernible by trial and error. As inpreviously-described examples, the helical structure 332 can be impartedby bending the catheter tube 322 to form one or more coils 334. Thecoils 334 can have a constant or variable diameter and height asdescribed above. The catheter tube 322 further comprises a plurality ofdrainage ports 336 disposed on the sidewall of the catheter tube 322 toallow urine to be drawn into the drainage lumen 324 of the catheter tube322 and to be directed from the body through the drainage lumen 324, forexample on the inwardly facing and/or outwardly facing sides of the coil334.

As shown in FIG. 38B, the inflatable element or balloon 350 can comprisean annular balloon-like structure having, for example, a generallyheart-shaped cross section and comprising a surface or cover 352defining a cavity 353. The cavity 353 is in fluid communication with aninflation lumen 354 extending parallel to the drainage lumen 324 definedby the catheter tube 322. The balloon 350 can be configured to beinserted in the tapered portion of the renal pelvis and inflated suchthat an outer surface 356 thereof contacts and rests against an innersurface of the ureter and/or renal pelvis. The inflatable element orballoon 350 can comprise a tapered inner surface 358 extendinglongitudinally and radially inward towards the catheter tube 322. Theinner surface 358 can be configured to direct urine toward the cathetertube 322 to be drawn into the drainage lumen 324. The inner surface 358can also be positioned to prevent fluid from pooling in the ureter, suchas around the periphery of the inflatable element or balloon 350. Theinflatable retention portion or balloon 350 is desirably sized to fitwithin the renal pelvis and can have a diameter ranging from about 10 mmto about 30 mm.

With reference to FIGS. 39A-40C, in some examples, an assembly 400including a ureteral catheter 412 comprising a retention portion 410 isillustrated. The retention portion 410 is formed from a porous and/orsponge-like material that is attached to a distal end 421 of a cathetertube 422. The porous material can be configured to channel and/or absorburine and direct the urine toward a drainage lumen 424 of the cathetertube 422. The retention portion 410 can be configured into afunnel-shaped support having an outer surface and an inner surface, andwherein the outer periphery 1002 or protective surface area 1001comprises the outer surface of the funnel-shaped support, and the one ormore drainage holes, ports or perforations in the porous material can bedisposed within the porous material or on the inner surface 426 of thefunnel-shaped support.

As shown in FIG. 40, the retention portion 410 can be a porous wedgeshaped-structure configured for insertion and retention in the patient'srenal pelvis. The porous material comprises a plurality of holes and/orchannels. Fluid can be drawn through the channels and holes, forexample, by gravity or upon inducement of negative pressure through thecatheter 412. For example, fluid can enter the wedge-shaped retentionportion 410 through the holes and/or channels and is drawn toward adistal opening 420 of the drainage lumen 424, for example, by capillaryaction, peristalsis, or as a result of the inducement of negativepressure in the holes and/or channels. In other examples, as shown inFIG. 40, the retention portion 410 comprises a hollow, funnel structureformed from the porous sponge-like material. As shown by arrow A, fluidis directed down an inner surface 426 of the funnel structure into thedrainage lumen 424 defined by the catheter tube 422. Also, fluid canenter the funnel structure of the retention portion 410 through holesand channels in the porous sponge-like material of a sidewall 428. Forexample, suitable porous materials can include open-celled polyurethanefoams, such as polyurethane ether. Suitable porous materials can alsoinclude laminates of woven or non-woven layers comprising, for example,polyurethane, silicone, polyvinyl alcohol, cotton, or polyester, with orwithout antimicrobial additives such as silver, and with or withoutadditives for modifying material properties such as hydrogels,hydrocolloids, acrylic, or silicone.

With reference to FIG. 41, according to another example, a retentionportion 500 of a ureteral catheter 512 comprises an expandable cage 530.The expandable cage 530 comprises one or more longitudinally andradially extending hollow tubes 522. For example, the tubes 522 can beformed from an elastic, shape memory material such as nitinol. The cage530 is configured to transition from a contracted state, for insertionthrough the patient's urinary tract, to a deployed state for positioningin the patient's ureters and/or kidney. The hollow tubes 522 comprise aplurality of drainage ports 534 which can be positioned on the tubes,for example, on radially inward facing sides thereof. The ports 534 areconfigured to permit fluid to flow or be drawn through the ports 534 andinto the respective tubes 522. The fluid drains through the hollow tubes522 into a drainage lumen 524 defined by a catheter body 526 of theureteral catheter 512. For example, fluid can flow along the pathindicated by the arrows 532 in FIG. 41. In some examples, when negativepressure is induced in the renal pelvis, kidneys, and/or ureters,portions of the ureter wall and/or renal pelvis may be drawn against theoutward facing surfaces of the hollow tubes 522. The drainage ports 534are positioned and configured so as not to be appreciably occluded byureteral structures upon application of negative pressure to the uretersand/or kidney.

In some examples, the ureteral catheter comprising a funnel support canbe deployed into a patient's urinary tract, and more specifically in therenal pelvis region/kidney using a conduit through the urethra and intothe bladder. The funnel support 6100 is in a collapsed state (shown inFIG. 36) and sheathed in a ureteral sheath 6102. To deploy the ureteralcatheter, the medical professional would insert a cystoscope into theurethra to provide a channel for tools to enter the bladder. Theureteral orifice would be visualized and guide wire would be insertedthrough the cystoscope and ureter until the tip of the guide wirereaches the renal pelvis. The cystoscope likely would be removed, and a“pusher tube” would be fed over the guide wire up to the renal pelvis.The guidewire would be removed while the “pusher tube” stays in place toact as deployment sheath. The ureteral catheter would be insertedthrough the pusher tube/sheath and the catheter tip would be actuatedonce it extends beyond the end of the pusher tube/sheath. The funnelsupport would expand radially to assume the deployed position.

Exemplary Ureteral Stents:

Referring now to FIG. 1A, in some examples, the ureteral stent 52, 54comprises an elongated body comprising a proximal end 62, a distal end58, a longitudinal axis, and at least one drainage channel that extendsalong the longitudinal axis from the proximal end to the distal end tomaintain patency of fluid flow between a kidney and a bladder of thepatient. In some examples, the ureteral stent further comprises apigtail coil or loop(s) on at least one of the proximal end or thedistal end. In some examples, the body of the ureteral stent furthercomprises at least one perforation on a sidewall thereof. In otherexamples, the body of the ureteral stent is essentially free of or freeof perforation(s) on a sidewall thereof.

Some examples of ureteral stents 52, 54 that can be useful in thepresent systems and methods include CONTOUR™ ureteral stents, CONTOURVL™ ureteral stents, POLARIS™ Loop ureteral stents, POLARIS™ Ultraureteral stents, PERCUFLEX™ ureteral stents, PERCUFLEX™ Plus ureteralstents, STRETCH™ VL Flexima ureteral stents, each of which arecommercially available from Boston Scientific Corporation of Natick,Mass. See “Ureteral Stent Portfolio”, a publication of Boston ScientificCorp., (July 2010), hereby incorporated by reference herein. TheCONTOUR™ and CONTOUR VL™ ureteral stents are constructed with softPercuflex™ Material that becomes soft at body temperature and isdesigned for a 365-day indwelling time. Variable length coils on distaland proximal ends allow for one stent to fit various ureteral lengths.The fixed length stent can be 6 F-8 F with lengths ranging from 20 cm-30cm, and the variable length stent can be 4.8 F-7 F with lengths of 22-30cm. Other examples of suitable ureteral stents include INLAY® ureteralstents, INLAY® OPTIMA® ureteral stents, BARDEX® double pigtail ureteralstents, and FLUORO-4™ silicone ureteral stent, each of which arecommercially available from C.R. Bard, Inc. of Murray Hill, N.J. See“Ureteral Stents”,http://www.bardmedical.com/products/kidney-stone-management/ureteral-stents/(Jan. 21, 2018), hereby incorporated by reference herein.

The stents 52, 54 can be deployed in one or both of the patient'skidneys or kidney area (renal pelvis or ureters adjacent to the renalpelvis), as desired. Typically, these stents are deployed by inserting astent having a nitinol wire therethrough through the urethra and bladderup to the kidney, then withdrawing the nitinol wire from the stent,which permits the stent to assume a deployed configuration. Many of theabove stents have a planar loop 58, 60 on the distal end (to be deployedin the kidney), and some also have a planar loop 62, 64 on the proximalend of the stent which is deployed in the bladder. When the nitinol wireis removed, the stent assumes the pre-stressed planar loop shape at thedistal and/or proximal ends. To remove the stent, a nitinol wire isinserted to straighten the stent and the stent is withdrawn from theureter and urethra.

Other examples of suitable ureteral stents 52, 54 are disclosed in PCTPatent Application Publication WO 2017/019974, which is incorporated byreference herein. In some examples, as shown, for example, in FIGS. 1-7of WO 2017/019974 and in FIG. 3 herein (same as FIG. 1 of WO2017/019974), the ureteral stent 100 can comprise: an elongated body 101comprising a proximal end 102, a distal end 104, a longitudinal axis106, an outer surface 108, and an inner surface 110, wherein the innersurface 110 defines a transformable bore 111 that extends along thelongitudinal axis 106 from the proximal end 102 to the distal end 104;and at least two fins 112 projecting radially away from the outersurface 108 of the body 101; wherein the transformable bore 111comprises: (a) a default orientation 113A (shown on the left in FIG. 59)comprising an open bore 114 defining a longitudinally open channel 116;and (b) a second orientation 113B (shown on the right in FIG. 59)comprising an at least essentially closed bore 118 or closed boredefining a longitudinally essentially closed drainage channel 120 alongthe longitudinal axis 106 of the elongated body 101, wherein thetransformable bore 111 is moveable from the default orientation 113A tothe second orientation 113B upon radial compression forces 122 beingapplied to at least a portion of the outer surface 108 of the body 101.

In some examples, as shown in FIG. 3, the drainage channel 120 of theureteral stent 100 has a diameter D which is reduced upon thetransformable bore 111 moving from the default orientation 113A to thesecond orientation 113B, wherein the diameter is reducible up to thepoint above where urine flow through the transformable bore 111 would bereduced. In some examples, the diameter D is reduced by up to about 40%upon the transformable bore 111 moving from the default orientation 113Ato the second orientation 113B. In some examples, the diameter D in thedefault orientation 113A can range from about 0.75 to about 5.5 mm, orabout 1.3 mm or about 1.4 mm. In some examples, the diameter D in thesecond orientation 113B can range from about 0.4 to about 4 mm, or about0.9 mm.

In some examples, one or more fins 112 comprise a flexible material thatis soft to medium soft based on the Shore hardness scale. In someexamples, the body 101 comprises a flexible material that is medium hardto hard based on the Shore hardness scale. In some examples, one or morefins have a durometer between about 15 A to about 40 A. In someexamples, the body 101 has a durometer between about 80 A to about 90 A.In some examples, one or more fins 112 and the body 101 comprise aflexible material that is medium soft to medium hard based on the Shorehardness scale, for example having a durometer between about 40 A toabout 70 A.

In some examples, one or more fins 112 and the body 101 comprise aflexible material that is medium hard to hard based on the Shorehardness scale, for example having a durometer between about 85 A toabout 90 A.

In some examples, the default orientation 113A and the secondorientation 113B support fluid or urine flow around the outer surface108 of the stent 100 in addition to through the transformable bore 111.

In some examples, one or more fins 112 extend longitudinally from theproximal end 102 to the distal end 104. In some examples, the stent hastwo, three or four fins.

In some examples, the outer surface 108 of the body has an outerdiameter in the default orientation 113A ranging from about 0.8 mm toabout 6 mm, or about 3 mm. In some examples, the outer surface 108 ofthe body has an outer diameter in the second orientation 113B rangingfrom about 0.5 mm to about 4.5 mm, or about 1 mm. In some examples, oneor more fins have a width or tip ranging from about 0.25 mm to about 1.5mm, or about 1 mm, projecting from the outer surface 108 of the body ina direction generally perpendicular to the longitudinal axis.

In some examples, the radial compression forces are provided by at leastone of normal ureter physiology, abnormal ureter physiology, orapplication of any external force. In some examples, the ureteral stent100 purposefully adapts to a dynamic ureteral environment, the ureteralstent 100 comprising: an elongated body 101 comprising a proximal end102, a distal end 104, a longitudinal axis 106, an outer surface 108,and an inner surface 110, wherein the inner surface 110 defines atransformable bore 111 that extends along the longitudinal axis 106 fromthe proximal end 102 to the distal end 104; wherein the transformablebore 111 comprises: (a) a default orientation 113A comprising an openbore 114 defining a longitudinally open channel 116; and (b) a secondorientation 113B comprising an at least essentially closed bore 118defining a longitudinally essentially closed channel 120, wherein thetransformable bore is moveable from the default orientation 113A to thesecond orientation 113B upon radial compression forces 122 being appliedto at least a portion of the outer surface 108 of the body 101, whereinthe inner surface 110 of the body 101 has a diameter D which is reducedupon the transformable bore 111 moving from the default orientation 113Ato the second orientation 113B, wherein the diameter is reducible up tothe point above where fluid flow through the transformable bore 111would be reduced. In some examples, the diameter D is reduced by up toabout 40% upon the transformable bore 111 moving from the defaultorientation 113A to the second orientation 113B.

Other examples of suitable ureteral stents are disclosed in US PatentApplication Publication US 2002/0183853 A1, which is incorporated byreference herein. In some examples, as shown, for example, in FIGS. 4, 5and 7 of US 2002/0183853 A1 and in FIGS. 4-6 herein (same as FIGS. 1 of4, 5 and 7 of US 2002/0183853 A1), the ureteral stent comprises anelongated, body 10 comprising a proximal end 12, a distal end 14 (notshown), a longitudinal axis 15, and at least one drainage channel (forexample, 26, 28, 30 in FIG. 4; 32, 34, 36 and 38 in FIG. 5; and 48 inFIG. 6) that extends along the longitudinal axis 15 from the proximalend 12 to the distal end 14 to maintain patency of fluid flow between akidney and a bladder of the patient. In some examples, the at least onedrainage channel is partially open along at least a longitudinal portionthereof. In some examples, the at least one drainage channel is closedalong at least a longitudinal portion thereof. In some examples, the atleast one drainage channel is closed along the longitudinal lengththereof. In some examples, the ureteral stent is radially compressible.In some examples, the ureteral stent is radially compressible to narrowthe at least one drainage channel. In some examples, the elongated body10 comprises at least one external fin 40 along the longitudinal axis 15of the elongated body 10. In some examples, the elongated body comprisesone to four drainage channels. The diameter of the drainage channel canbe the same as described above.

Systems for Inducing Negative Pressure

In some examples, a system for inducing negative pressure in a portionof a urinary tract of a patient or for removing fluid from the urinarytract of a patient is provided, comprising: a ureteral stent or ureteralcatheter for maintaining patency of fluid flow between at least one of akidney and a bladder of the patient; a bladder catheter comprising adrainage lumen for draining fluid from the bladder of the patient; and apump in fluid communication with a distal end of the drainage lumen, thepump comprising a controller configured to actuate the pump to applynegative pressure to the proximal end of the catheter to induce negativepressure in a portion of the urinary tract of the patient to removefluid from the urinary tract of the patient.

In some examples, a system for inducing negative pressure in a portionof a urinary tract of a patient is provided, the system comprising: (a)a ureteral catheter comprising a distal portion for insertion within thepatient's kidney and a proximal portion; (b) a bladder cathetercomprising a distal portion for insertion within the patient's bladderand a proximal portion for application of negative pressure, theproximal portion extending outside of the patient's body; and (c) a pumpexternal to the patient's body for application of negative pressurethrough both the bladder catheter and the ureteral catheter, which inturn causes fluid from the kidney to be drawn into the ureteralcatheter, through both the ureteral catheter and the bladder catheter,and then outside the patient's body.

In some examples, a system for inducing negative pressure in a portionof a urinary tract of a patient is provided, the system comprising: (a)at least one ureteral catheter, the at least one ureteral cathetercomprising a distal portion for insertion within the patient's kidneyand a proximal portion; (b) a bladder catheter comprising a distalportion for insertion within the patient's bladder and a proximalportion for receiving negative pressure from a negative pressure source,wherein at least one of the at least one ureteral catheter(s) or thebladder catheter comprises (a) a proximal portion; and (b) a distalportion, the distal portion comprising a retention portion thatcomprises one or more protected drainage holes, ports or perforationsand is configured to establish an outer periphery or protective surfacearea that inhibits mucosal tissue from occluding the one or moreprotected drainage holes, ports or perforations upon application ofnegative pressure through the catheter; and (c) a negative pressuresource for application of negative pressure through both the bladdercatheter and the ureteral catheter(s), which in turn causes fluid fromthe kidney to be drawn into the ureteral catheter(s), through both theureteral catheter(s) and the bladder catheter, and then outside of thepatient's body.

In some examples, a system for inducing negative pressure in a portionof a urinary tract of a patient, the system comprising: (a) at least oneureteral catheter, the at least one ureteral catheter comprising adistal portion for insertion within the patient's kidney and a proximalportion; (b) a bladder catheter comprising a distal portion forinsertion within the patient's bladder and a proximal portion forreceiving a pressure differential, wherein the pressure differentialcauses fluid from the kidney to be drawn into the ureteral catheter(s),through both the ureteral catheter(s) and the bladder catheter, and thenoutside of the patient's body, the pressure differential being appliedto increase, decrease and/or maintain fluid flow therethrough, whereinat least one of the at least one ureteral catheter(s) or the bladdercatheter comprises (a) a proximal portion; and (b) a distal portion, thedistal portion comprising a retention portion that comprises one or moreprotected drainage holes, ports or perforations and is configured toestablish an outer periphery or protective surface area that inhibitsmucosal tissue from occluding the one or more protected drainage holes,ports or perforations upon application of differential pressure throughthe catheter.

With reference to FIGS. 1A, 1B, 1C, 1F, 1P, 1U, 2A, 2B, 7A and 7B, anexemplary system 1100 for inducing negative pressure in a urinary tractof a patient for increasing renal perfusion is illustrated. The system1100 comprises one or two ureteral catheters 1212 (or alternativelyureteral stents shown in FIG. 1A) connected to a fluid pump 2000 forgenerating the negative pressure. More specifically, the patient'surinary tract comprises the patient's right kidney 2 and left kidney 4.The kidneys 2, 4 are responsible for blood filtration and clearance ofwaste compounds from the body through urine. Urine or fluid produced bythe right kidney 2 and the left kidney 4 is drained into a patient'sbladder 10 through tubules, namely a right ureter 6 and a left ureter 8,which are connected to the kidneys at the renal pelvis 20, 21. Urine maybe conducted through the ureters 6, 8 by peristalsis of the ureterwalls, as well as by gravity. The ureters 6, 8 enter the bladder 10through a ureter orifice or opening 16. The bladder 10 is a flexible andsubstantially hollow structure adapted to collect urine until the urineis excreted from the body. The bladder 10 is transitionable from anempty position (signified by reference line E) to a full position(signified by reference line F). Normally, when the bladder 10 reaches asubstantially full state, fluid or urine is permitted to drain from thebladder 10 to a urethra 12 through a urethral sphincter or opening 18located at a lower portion of the bladder 10. Contraction of the bladder10 can be responsive to stresses and pressure exerted on a trigoneregion 14 of the bladder 10, which is the triangular region extendingbetween the ureteral openings 16 and the urethral opening 18. Thetrigone region 14 is sensitive to stress and pressure, such that as thebladder 10 begins to fill, pressure on the trigone region 14 increases.When a threshold pressure on the trigone region 14 is exceeded, thebladder 10 begins to contract to expel collected urine through theurethra 12.

As shown in FIGS. 1, 2A, 7A and 7B, distal portions of the ureteralcatheter(s) are deployed in the renal pelvis 20, 21 near the kidneys 2,4. Proximal portions of the one or more of the catheter(s) 1212 emptyinto the bladder, into the urethra or outside of the body. In someexamples, the proximal portion 1216 of the ureteral catheter 1212 is influid communication with the distal portion or end 136 of the bladdercatheter 56, 116. A proximal portion 1216 of the bladder catheter 56,116 is connected to a source of negative pressure, such as a fluid pump2000. The shape and size of the connector can be selected based on thetype of pump 2000 being used. In some examples, the connector can bemanufactured with a distinctive configuration so that it can only beconnected to a particular pump type, which is deemed to be safe forinducing negative pressure in a patient's bladder, ureter, or kidneys.In other examples, as described herein, the connector can be a moregeneric configuration adapted for attachment to a variety of differenttypes of fluid pumps. System 1100 is but one example of a negativepressure system for inducing negative pressure that can be used with thebladder catheters disclosed herein.

Referring now to FIGS. 1A, 1B, 1C, 1F, 1P, 1U, 2A, 2B 7A, 7B, 17, insome examples the system 50, 100 comprises a bladder catheter 116. Thedistal ends 120, 121 of the ureteral catheters 112, 114 can draindirectly into the bladder, and the fluid can drain through the bladdercatheter 116, and optionally along the sides of the bladder cathetertube.

Exemplary Bladder Catheters

Any of the ureteral catheters disclosed herein can be used as bladdercatheters useful in the present methods and systems. In some examples,the bladder catheter 116 comprises a retention portion 123 or deployableseal and/or anchor 136 for anchoring, retaining, and/or providingpassive fixation for indwelling portions of the urine collectionassembly 100 and, in some examples, to prevent premature and/or untendedremoval of assembly components during use. The retention portion 123 oranchor 136 is configured to be located adjacent to the lower wall of thepatient's bladder 10 (shown in FIGS. 1A, 1B, 1C, 1F, 1P, 1U, 2A, 2B, 7A,7B, 17) to prevent patient motion and/or forces applied to indwellingcatheters 112, 114, 116 from translating to the ureters. The bladdercatheter 116 comprises an interior of which defines a drainage lumen 140configured to conduct urine from the bladder 10 to an external urinecollection container 712 (shown in FIG. 44). In some examples, thebladder catheter 116 tube size can range from about 8 Fr to about 24 Fr.In some examples, the bladder catheter 116 can have an external tubediameter ranging from about 2.7 to about 8 mm. In some examples, thebladder catheter 116 can have an internal diameter ranging from about2.16 to about 10 mm. The bladder catheter 116 can be available indifferent lengths to accommodate anatomical differences for genderand/or patient size. For example, the average female urethra length isonly a few inches, so the length of a tube 138 can be rather short. Theaverage urethra length for males is longer due to the penis and can bevariable. It is possible that woman can use bladder catheters 116 withlonger length tubes 138 provided that the excess tubing does notincrease difficulty in manipulating and/or preventing contamination ofsterile portions of the catheter 116. In some examples, a sterile andindwelling portion of the bladder catheter 116 can range from about 1inch to 3 inches (for women) to about 20 inches for men. The totallength of the bladder catheter 116 including sterile and non-sterileportions can be from one to several feet.

In some examples, such as are shown in FIGS. 1A, 1B, 1C, 1F, 1P, 1U, 2A,2B, 7A and 7B, the distal portion 136 of the bladder catheter 56, 116comprises a retention portion 123 that includes one or more drainageholes, ports or perforations 142 and is configured to establish an outerperiphery 1002 or protective surface area 1001 that inhibits mucosaltissue from occluding the one or more drainage holes, ports orperforations 142 upon the application of negative pressure by the pump710, 2000.

In some examples in which the retention portion 123 comprises a tube138, the tube 138 can comprise one or more drainage holes, ports orperforations 142 configured to be positioned in the bladder 10 fordrawing urine into the drainage lumen 140. For example, fluid or urinethat flows into the patient's bladder 10 from the ureteral catheters112, 114 is expelled from the bladder 10 through the ports 142 anddrainage lumen 140. The drainage lumen 140 may be pressurized to anegative pressure to assist in fluid collection.

In some examples, such as are shown in FIGS. 1A, 1B, 1C, 1F, 1P, 1U, 2A,2B, 7A and 7B, the one or more drainage holes, ports or perforations142, 172 of the bladder catheter 56, 116, like the ureteral cathetersdiscussed above, are disposed on a protected surface area or innersurface area 1000 of the retention portion 123, and wherein, uponapplication of negative pressure, the mucosal tissue 1003, 1004 conformsor collapses onto the outer periphery 1002 or protective surface area1001 of the retention portion 173 of the bladder catheter 56, 116 and isthereby prevented or inhibited from occluding the one or more of theprotected drainage holes, ports or perforations 172 of the bladdercatheter 56, 116

With specific reference to FIGS. 1A, 1B, 1C, 1F, 1P, 1U, 2A, 2B, 7A and7B, the retention portion 123 or deployable seal and/or anchor 136 isdisposed at or adjacent to a distal end 148 of the bladder catheter 116.The retention portion 123 or deployable anchor 136 is configured totransition between a contracted state for insertion into the bladder 10through the urethra 12 and urethral opening 18 and a deployed state. Theretention portion 123 or deployable anchor 136 is configured to bedeployed in and seated adjacent to a lower portion of the bladder 10and/or against the urethral opening 18. For example, the retentionportion 123 or deployable anchor 136 can be positioned adjacent to theurethral opening 18 to enhance suction of a negative pressure applied tothe bladder 10 or to partially, substantially, or entirely seal thebladder 10 to ensure that urine in the bladder 10 is directed throughthe drainage lumen 140 and to prevent leakage to the urethra 12. For abladder catheter 116 including an 8 Fr to 24 Fr elongated tube 138, theretention portion 123 or deployable anchor 136 can have a diameter ofabout 10 mm to about 100 mm) in the deployed state.

Exemplary Bladder Anchor Structures

Any of the ureteral catheters disclosed herein can be used as bladdercatheters useful in the present methods and systems. For example, thebladder catheter can comprise a mesh as a bladder anchor, such as isshown in FIGS. 1A, 1B and 7B. In another example, the bladder catheter116 can comprise a coil 36, 38, 40, 183, 184, 185, 334, 1210 as abladder anchor, such as is shown in FIGS. 1C-1W and 7A. In anotherexample, the bladder catheter 116 can comprise a mesh funnel 57 as abladder anchor, such as is shown in FIG. 7B. In another example, thebladder catheter 116 can comprise a funnel 150 as a bladder anchor, suchas is shown in FIG. 17. Regardless of the embodiment selected, theretention portion 123 creates an outer periphery 1002 or protectivesurface area 1001 to prevent the tissues 1003, 1004 from contracting orcollapsing into the fluid column under negative pressure.

In some examples, the retention portion 123 comprises a coiled retentionportion similar to the retention portions of the ureteral cathetersdescribed in connection with FIGS. 2A and 7A-14. In some examples suchas are shown in FIGS. 1C-1E, 1U-1W, the coiled retention portion 123 cancomprise a plurality of helical coils 36, 38, 40 or 438, 436, 432arranged such that an outer periphery 1002 or outer region of thehelical coils 36, 38, 40 or 438, 436, 432 contacts and supports bladdertissue 1004 to inhibit occlusion or blockage of protected drainageholes, ports or perforations 172 positioned in protected surface areasor inner surface areas of the helical coils 36, 38, 40 or 438, 436, 432.

The coiled retention portion 123 can comprise at least the first coil36, 438 having an outer diameter D1 (see FIG. 1E), at least a secondcoil 38, 436 having an outer diameter D2, and at least a third coil 40,432 having an outer diameter D3. The diameter D3 of the distal-most orthird coil 40, 432 can be smaller than a diameter of either the firstcoil 36, 438 or the second coil 38, 436. Accordingly, a diameter of thecoils 36, 38, 40 or 438, 436, 432, and/or a step distance or heightbetween adjacent coils 36, 38, 40 or 438, 436, 432 can vary in a regularor irregular manner. In some examples, the plurality of coils 36, 38, 40or 438, 436, 432 can form a tapered or reverse pyramid shape in whichD1>D2>D3. In some examples, the coiled retention portion 123 cancomprise a plurality of similarly sized coils or, for example, caninclude a plurality of proximal similarly sized coils and a distal-mostcoil having a smaller diameter than other coils of the plurality ofcoils. The diameter of the coils 36, 38, 40 or 438, 436, 432 anddistance or height between adjacent coils is selected so that theretention portion 123 remains in the bladder for a desired period oftime, such as hours, days or up to about 6 months. The coiled retentionportion 123 can be large enough so that it remains in the bladder 10 anddoes not pass into the urethra until the catheter is ready to be removedfrom the bladder 10. For example, the outer diameter D1 of the proximalmost or first coil 36 438 can range from about 2 mm to 80 mm. The outerdiameter D2 of the second coil 38, 436 can range from about 2 mm to 60mm. The distal-most or third coil 40, 432 can have an outer diameter D3ranging from about 1 mm to 45 mm. The diameter of the coil tube canrange from about 0.33 mm to 9.24 mm (about 1 Fr to about 28 Fr (Frenchcatheter scale).

The configurations, sizes and positions of the holes, ports orperforations 142, 172 can be any of the configurations, sizes andpositions discussed above for the ureteral or other catheters. In someexamples, holes, ports or perforations 142 are present on the outerperiphery 1002 or protective surface area 1001 and protected holes,ports or perforations 172 are present on the protected surface areas orinner surface areas 1000. In some examples, the outer periphery 1002 orprotective surface area 1001 is essentially free of or free of holes,ports or perforations 142, and the protected holes, ports orperforations 172 are present on the protected surface areas or innersurface areas 1000.

The retention portion 416 shown in FIGS. 1U-1W is a coiled retentionportion comprising a plurality of coils wrapped around a substantiallylinear or straight portion 430 of the elongated tube 418. In someexamples, the coiled retention portion 416 comprises a straight portion430 and a distal-most coil 432 formed from a bend 434 of from about 90degrees to 180 degrees in the elongated tube 418. The retention portion416 further comprises one or more additional coils, such as a second ormiddle coil 436 and a third or proximal most coil 438, which are wrappedaround the straight portion 430. The elongated tube 418 can furthercomprise a distal end 440 after the proximal most coil 438. The distalend 440 can be closed or can be open to receive urine or fluid from thebladder 10.

An area of two-dimensional slices 34 (shown in FIG. 1E) of thethree-dimensional shape 32 defined by the deployed expandable retentionportion 123 in a plane transverse to a central axis A of the expandableretention portion 16 can decrease towards the distal end 22 of theexpanded or deployed retention portion 123, giving the retention portion123 a pyramid or reversed conical shape. In some examples, a maximumcross-sectional area of the three-dimensional shape 32 defined by thedeployed or expanded retention portion 123 in a plane transverse to thecentral axis A of the deployed or expanded retention portion 132 canrange from about 100 mm² to 1500 mm², or about 750 mm².

Other examples of a catheter device 10 are shown in FIGS. 1F-1J. Theretention portion 123 of the catheter device 10 comprises a basketshaped structure or support cap 212 of a bladder superior wall support210 or outer periphery 1002, configured to be disposed within a distalportion of the tube 12 in a retracted position and to extend from thedistal end of the tube 12 in a deployed position. The bladder superiorwall support 210 comprises a support cap 212 configured to support asuperior wall or bladder tissue 1004 and a plurality of support members,such as legs 214, connected to a proximal surface of the support cap212. The legs 214 can be positioned so that the cap 212 is spaced apartfrom an open distal end of the drainage tube 12. For example, the legs214 can be configured to maintain a gap, cavity, or space of distance D1between an open distal end 30 of the tube 12 and the support cap 212.The distance D1 can range from about 1 mm to about 40 mm, or about 5 mmto about 40 mm. The height D2 of the bladder superior wall support 210or retention portion can range from about 25 mm to about 75 mm, or about40 mm. The maximum diameter of the support cap 212 can range from about25 mm to about 60 mm in the deployed state, and preferably range fromabout 35 mm and 45 mm.

In some examples, the legs 214 comprise flexible tines, which can beformed from a flexible or shape memory material, such as a nickeltitanium. The number of legs can range from about 3 to about 8. Thelength of each leg can range from about 25 mm to about 100 mm, or longerif the deployment mechanism is external to the patient's body. The widthand/or thickness, e.g., diameter, of each leg can range from about 0.003inches to about 0.035 inches.

In some examples, the support cap 212 can be a flexible cover 216mounted to and supported by the legs 214. The flexible cover 216 can beformed from a flexible, soft and/or resilient material, such as siliconeor Teflon®, for preventing fluid from passing through the cover 216, aporous material, or combinations thereof. In some examples, the flexiblematerial is formed from a material which does not appreciably abrade,irritate, or damage the mucosal lining of the bladder wall or theurethra when positioned adjacent to the mucosal lining, such as siliconeor Teflon® materials or porous materials. The thickness of the cover 216can range from about 0.05 mm to about 0.5 mm. In some examples, theflexible cover 216 and legs 214 are sufficiently structurally rigid sothat the cover 216 and legs 214 maintain their form when contacted bythe superior wall or bladder tissue 1004. Accordingly, the legs 214 andflexible cover 216 prevent the bladder from collapsing and occludingperforations on the retention portion 6 and/or an open distal end 30 ofthe tube 12. Also, the legs 214 and flexible cover 216 effectively keepthe trigone region and ureteral orifices open so that negative pressurecan draw urine into the bladder and drainage tube 12. As discussedherein, if the bladder were permitted to collapse too far, flaps oftissue would extend over the ureter openings, thereby preventingnegative pressure from being transmitted to the ureteral catheter(s),ureteral stent(s) and/or ureters and thereby inhibit drawing of urineinto the bladder.

In some examples, the catheter device 10 further comprises a drainagetube 218. As shown in FIGS. 1G-1J, the drainage tube 218 can comprise anopen distal end 220 positioned adjacent to or extending from the opendistal end 30 of the tube 12. In some examples, the open distal end 220of the drainage tube 218 is the only opening for drawing urine from thebladder into the interior of the drainage tube 218. In other examples, adistal portion of the drainage tube 218 may comprise perforations (notshown in FIGS. 1G-1I) or holes, ports or perforations 174 on a sidewall222 thereon, as shown in FIG. 1J. The holes, ports or perforations 174can provide additional spaces for drawing urine into the interior of thedrainage tube 218, thereby ensuring that fluid collection can continueeven if the open distal end 220 of the drainage tube 218 is occluded.Also, holes, ports or perforations 174 can increase surface areaavailable for drawing fluid into the drainage tube 218, therebyincreasing efficiency and/or fluid collection yield.

In some examples, a distal most portion of the support cap 212 cancomprise a sponge or pad 224, such as a gel pad. The pad 224 can bepositioned to contact and press against the superior bladder wall orbladder tissue 1004 for the purpose of preventing drainage, aspiration,or other trauma to the bladder 10 during negative pressure treatment.

With reference to FIG. 1J, the bladder superior wall support 210comprises a support cap 212 and a plurality of legs 214. As inpreviously described examples, the bladder superior wall support 210 iscapable of being moved between a retracted position, in which thesupport 210 is at least partially retracted in a conduit or tube 12, anda deployed position to support the superior wall of the bladder. In someexamples, the catheter device 10 also includes a drainage tube 218extending from the open distal end 30 of the conduit or tube 12. Unlikein the previously-described examples, the support cap 212 shown in FIG.4 comprises an inflatable balloon 226. The inflatable balloon 226 can bea substantially semi-spherical and can comprise a curved distal surface228 configured to contact and support at least a portion of the superiorbladder wall or bladder tissue 1004 when deployed.

In some examples, the drainage tube 218 comprises a perforated portion230 extending between the open distal end 30 of the tube 12 and thesupport structure 212. The perforated portion 230 is positioned to drawfluid into an interior of the drainage tube 218 so that it can beremoved from the bladder 100. Desirably, the perforated portion 230 ispositioned so as not to be occluded either by the deployed support cap212 or the bladder wall when negative pressure is applied thereto. Thedrainage tube 218 can comprise or be positioned adjacent to an inflationlumen 232 for providing fluid or gas to an interior 234 of the balloon226 for inflating the balloon 226 from its contracted position to thedeployed position. For example, as shown in FIG. 1J, the inflation lumen232 can be disposed within the drainage tube 218.

With reference to FIG. 1K, an exemplary retention portion 6, 123 of aurine collection catheter device 10 including multiple coiled drainagelumens, generally denoted as lumens 218, is illustrated. The retentionportion 6 comprises the tube 12 having a distal open end 30. Thedrainage lumens 218 are positioned partially within the tube 12. In adeployed position, the draining lumens 218 are configured to extend fromthe open distal end 30 of the tube 12 and to conform to a coiledorientation. The drainage lumens 218 can be separate for the entirelength of the catheter device 10, or may empty into a single drainagelumen defined by the tube 12. In some examples, as shown in FIG. 6, thedrainage lumens 218 can be pigtail coils having one or more coils 244.Unlike in the previously described example, the pigtail coils 244 arecoiled about an axis that is not coextensive with an axis C of anuncoiled portion of the tube. Instead, as shown in FIG. 6, the pigtailcoils can be coiled about an axis D that is approximately perpendicularto the axis C of the tube 12. In some examples, the drainage lumens 218can comprise holes, ports or perforations (not shown in FIG. 1K),similar to perforations 132, 133 in FIG. 9A or 9B, for drawing fluidfrom the bladder into an interior of the drainage lumens 218. In someexamples, the perforations can be positioned on a radially inwardlyfacing side 240 and/or outwardly facing side of the coiled portions ofthe drainage lumens. As previously described, perforations positioned onradially inwardly facing sides of the drainage lumens 218 or tube 12 areless likely to be occluded by the bladder walls during application ofnegative pressure to the bladder. Urine can also be drawn directly intoone or more drainage lumens defined by the tube 12. For example, ratherthan being drawing into the drainage lumen(s) 218 through theperforations 230, urine can be drawn directly through the open distalend 30 and into a drainage lumen defined by the tube 12.

With reference to FIGS. 1L and 1M, another example of a retentionportion 123 is shown. A fluid receiving portion or distal end portion 30a of the catheter device 10 a is shown in a contracted position in FIG.1L, and in a deployed position in FIG. 1M. The distal end 30 a includesopposing bladder wall supports 19 a, 19 b for supporting the superiorand inferior bladder walls 1004. For example, the distal end portion 30a can comprise a proximal sheath 20 a and a distal sheath 22 a. Eachsheath 20 a, 22 a extends between a slidable ring or collar 24 a andstationary or mounted ring or collar 28 a. The sheaths 20 a, 22 a areformed from a flexible, non-porous material, such as silicon or any ofthe materials discussed herein. The sheaths 20 a, 22 a are held togetherby one or more flexible wires or cables 26 a. The sheaths 20 a, 22 a canalso be connected by one or more rigid members, such as supports 32 a.In some examples, the supports 32 a can be tines formed from a flexible,shape-memory material, such as nickel titanium. The supports 32 a arepositioned to provide support for the proximal sheath 20 a and toprevent the distal end 30 a from collapsing when it is in the deployedposition. In the contracted position, the collars 24 a, 28 a arepositioned apart from one another, such that the sheaths 20 a, 22 a arestretched or folded against the cable 26 a and supports 32 a. In thedeployed position, the slidable collars 24 a are moved toward thestationary collars 28 a, allowing the sheaths 20 a, 22 a to unfold fromthe central cables 26 a and to form a substantially flat disk-shapedstructure.

In use, the distal end 30 a of the catheter device 10 a is inserted intothe bladder of a patient in the contracted position. Once inserted inthe bladder, the distal sheath 22 a is released by sliding the slidablecollar 24 a in a distal direction toward the stationary collar 28 a.Once the distal sheath 22 a is deployed, the proximal sheath 20 a isreleased or deployed in a similar manner by sliding the slidable collar24 a in the proximal direction toward the respective stationary collar28 a. At this point, the proximal sheath 20 a is floating within thebladder, and is not positioned or sealed against the inferior wall ofthe bladder. Pressure against the distal sheath 22 a caused bycollapsing of the bladder is transferred to the proximal sheath 20 athrough the supports 32 a and causes the proximal sheath 20 a to movetoward the desired position adjacent to the opening of the urethra. Oncethe proximal sheath 20 a is in place, a seal over the urethra openingmay be created. The proximal sheath 20 a assists in maintaining anegative pressure within the bladder and prevents air and/or urine fromexiting the bladder through the urethra.

With reference to FIGS. 1N-1T, retention portions 123 comprising aninflatable support cap, such as an annular balloon 310, positioned tocontact the superior wall of the bladder 10 to prevent the bladder 10from contracting and occluding either fluid port(s) 312 of the catheterdevice 10 or the ureteral openings of the bladder. In some examples, adistal end portion 30 of the tube 12 extends through a central opening314 of the balloon 310. The distal end portion 30 of the tube 12 canalso contact the superior bladder wall.

Referring now to FIGS. 1N and 1O, in some examples, the tube 12comprises a fluid access portion 316 positioned proximal to the balloon310 and extending through a sidewall of the tube 12. The fluid accessportion 316 can comprise a filter 318 (shown in FIG. 1O) disposed abouta central lumen of the tube 12. In some examples, a sponge material 320can be positioned over the filter 318 for increased absorbance of fluidwithin the bladder. For example, the sponge material 320 can beinjection molded over the filter 318. In use, urine is absorbed by thesponge material 320 and, upon application of negative pressure throughthe tube 12, passes through the filter 318 and into the central lumen ofthe tube 12.

Referring now to FIGS. 1P-1R, in another example, the support cap, suchas the annular balloon 310, comprises a substantially bulbous distalportion 322 configured to contact and support the superior bladder wall.The balloon 310 further comprises a plurality of proximally extendinglobes 324. For example, the balloon 310 can comprise three lobes 324spaced equidistantly around a portion of the tube 12 proximal to theballoon 310. As shown in FIG. 1R, the fluid ports 312 can be positionedbetween adjacent lobes 324. In this configuration, the lobes 324 andbulbous distal portion 322 contact the bladder wall, which prevents thebladder wall from blocking or occluding the fluid ports 312.

Referring now to FIGS. 1S and 1T, in another example, the annularballoon 310 is provided with a flattened and elongated shape. Forexample, the annular balloon 310 can have a substantially teardropshaped radial cross section as shown in FIG. 1T, with a narrower portion326 thereof positioned adjacent to the tube 12 and the enlarged orbulbous portion 328 positioned on the radially outwardly facing sidethereof. The flatted annular balloon 310 is configured to span andoptionally seal the periphery of the trigone region of the bladder suchthat when deployed in the bladder, the outer circumference of theballoon 310 extends radially beyond the ureteral openings. For example,when positioned in the patient's bladder, the central opening 314 of theballoon 310 can be configured to be positioned above the trigone region.Fluid port(s) 312 can be positioned proximal to the central portionballoon 310, as shown in FIG. 1T. Desirably, the fluid port(s) 312 arepositioned between the central opening 314 of the balloon and thetrigone region. When the bladder contracts from application of negativepressure, the bladder wall is supported by the outer circumference ofthe balloon 310 to avoid blocking the ureter openings. Accordingly, inthis configuration, the balloon 310 contacts and prevents the bladderwall from blocking or occluding the fluid ports 312. In a similarmanner, as discussed herein, the balloon 310 keeps the trigone regionopen so that urine can be drawn from the ureters into the bladderthrough the ureteral openings.

With reference to FIG. 41, in another example of a bladder catheter, anexpandable cage 530 can anchor the bladder catheter in the bladder. Theexpandable cage 530 comprises a plurality of flexible members or tinesextending longitudinally and radially outward from a catheter body of abladder catheter which, in some examples, can be similar to thosediscussed above with respect to the retention portion of the ureteralcatheter of FIG. 41. The members can be formed from a suitable elasticand shape memory material such as nitinol. In a deployed position, themembers or tines are imparted with a sufficient curvature to define aspherical or ellipsoid central cavity. The cage is attached to an opendistal open end of the catheter tube or body, to allow access to adrainage lumen defined by the tube or body. The cage is sized forpositioning within the lower portion of the bladder and can define adiameter and length ranging from 1.0 cm to 2.3 cm, and preferably about1.9 cm (0.75 in).

In some examples, the cage further comprises a shield or cover overdistal portions of the cage to prevent or reduce the likelihood thattissue, namely, the distal wall of the bladder, will be caught orpinched as a result of contact with the cage or member. Morespecifically, as the bladder contracts, the inner distal wall of thebladder comes into contact with the distal side of the cage. The coverprevents the tissue from being pinched or caught, may reduce patientdiscomfort, and protect the device during use. The cover can be formedat least in part from a porous and/or permeable biocompatible material,such as a woven polymer mesh. In some examples, the cover encloses allor substantially all of the cavity. In some examples, the cover coversonly about the distal ⅔, about the distal half, or about the distalthird portion or any amount, of the cage 210.

The cage and cover are transitionable from a contracted position, inwhich the members are contracted tightly together around a centralportion and/or around the bladder catheter 116 to permit insertionthrough a catheter or sheath to the deployed position. For example, inthe case of a cage constructed from a shape memory material, the cagecan be configured to transition to the deployed position when it iswarmed to a sufficient temperature, such as body temperature (e.g., 37°C.). In the deployed position, the cage has a diameter D that ispreferably wider than the urethral opening, and prevents patient motionfrom translating through the ureteral catheters 112, 114 to the ureters.The open arrangement of the members 212 or tines does not obstruct orocclude the distal opening 248 and/or drainage ports of the bladdercatheter 216, making manipulation of the catheters 112, 114 easier toperform.

It is understood that any of the above-described bladder catheters mayalso be useful as ureteral catheters.

The bladder catheter is connected to the vacuum source, such as pumpassembly 710 by, for example, flexible tubing 166 defining a fluid flowpath.

Exemplary Fluid Sensors:

With reference again to FIGS. 1A, 1B, 1C, 1F, 1P, 1U, 2A, 2B, in someexamples, the system or assembly 100, 700, 1100 further comprises one ormore sensors 174 for monitoring physical parameters or fluidcharacteristics of fluid or urine being collected from the ureters 6, 8and/or bladder 10. The one or more physiological sensors 174 associatedwith the patient can be configured to provide information representativeof at least one physical parameter to a controller. As discussed hereinin connection with FIG. 44, information obtained from the sensors 174can be transmitted to a central data collection module or processor andused, for example, to control operation of an external device, such asthe pump 710 (shown in FIG. 44). The sensors 174 can be integrallyformed with one or more of the catheters 112, 114, 116 such as, forexample, embedded in a wall of the catheter body or tube and in fluidcommunication with drainage lumens 124, 140. In other examples, one ormore of the sensors 174 can be positioned in a fluid collectioncontainer 712 (shown in FIG. 44) or in internal circuitry of an externaldevice, such as the pump 710.

Exemplary sensors 174 that can be used with the urine collectionassembly 100 can comprise one or more of the following sensor types. Forexample, the catheter assembly 100 can comprise a conductance sensor orelectrode that samples conductivity of urine. The normal conductance ofhuman urine is about 5-10 mS/m. Urine having a conductance outside ofthe expected range can indicate that the patient is experiencing aphysiological problem, which requires further treatment or analysis. Thecatheter assembly 100 can also comprise a flow meter for measuring aflow rate of urine through the catheter(s) 112, 114, 116. Flow rate canbe used to determine a total volume of fluid excreted from the body. Thecatheter(s) 112, 114, 116 can also comprise a thermometer for measuringurine temperature. Urine temperature can be used to collaborate theconductance sensor. Urine temperature can also be used for monitoringpurposes, as urine temperature outside of a physiologically normal rangecan be indicative of certain physiological conditions. In some examples,the sensors 174 can be urine analyte sensors configured to measure aconcentration of creatinine and/or proteins in urine. For example,various conductivity sensors and optical spectrometry sensors may beused for determining analyte concentration in urine. Sensors based oncolor change reagent test strips may also be used for this purpose.

Method of Insertion of a System:

Having described the system 100 comprising the ureteral catheter(s)and/or ureteral stent(s) and bladder catheter, some examples of methodsfor insertion and deployment of the ureteral stent(s) or ureteralcatheter(s) and bladder catheter will now be discussed in detail.

In some examples, a method for inducing negative pressure in a portionof a urinary tract of a patient is provided, the method comprising:deploying a ureteral catheter into a ureter of a patient to maintainpatency of fluid flow between a kidney and a bladder of the patient, theureteral catheter comprising a distal portion for insertion within thepatient's kidney and a proximal portion; deploying a bladder catheterinto the bladder of the patient, wherein the bladder catheter comprisesa distal portion for insertion within the patient's bladder and aproximal portion for application of negative pressure, the proximalportion extending outside of the patient's body; and applying negativepressure to the proximal end of the bladder catheter to induce negativepressure in a portion of the urinary tract of the patient to removefluid from the patient. In some examples, at least one of the ureteralcatheter or the bladder catheter comprises (a) a proximal portion; and(b) a distal portion, the distal portion comprising a retention portionthat comprises one or more protected drainage holes, ports orperforations and is configured to establish an outer periphery orprotective surface area that inhibits mucosal tissue from occluding theone or more protected drainage holes, ports or perforations uponapplication of negative pressure through the catheter.

With reference to FIG. 42A, an example of steps for positioning a systemin a patient's body and, optionally, for inducing negative pressure in apatient's urinary tract, such as bladder, ureter and/or kidneys areillustrated. As shown at box 610, a medical professional or caregiverinserts a flexible or rigid cystoscope through the patient's urethra andinto the bladder to obtain visualization of the ureteral orifices oropenings. Once suitable visualization is obtained, as shown at box 612,a guidewire is advanced through the urethra, bladder, ureteral opening,ureter, and to a desired fluid collection position, such as the renalpelvis of the kidney. Once the guidewire is advanced to the desiredfluid collection position, a ureteral stent or ureteral catheter of thepresent invention (examples of which are discussed in detail above) isinserted over the guidewire to the fluid collection position, as shownat box 614. In some examples, the location of the ureteral stent orureteral catheter can be confirmed by fluoroscopy, as shown at box 616.Once the position of the distal end of the ureteral stent or ureteralcatheter is confirmed, as shown at box 618, the retention portion of theureteral catheter can be deployed. For example, the guidewire can beremoved from the catheter, thereby allowing the distal end and/orretention portion to transition to a deployed position. In someexamples, the deployed distal end portion of the catheter does notentirely occlude the ureter and/or renal pelvis, such that urine ispermitted to pass outside the catheter and through the ureters into thebladder. Since moving the catheter can exert forces against urinarytract tissues, avoiding complete blockage of the ureters avoidsapplication of force to the ureter sidewalls, which may cause injury.

After the ureteral stent or ureteral catheter is in place and deployed,the same guidewire can be used to position a second ureteral stent orsecond ureteral catheter in the other ureter and/or kidney using thesame insertion and positioning methods described herein. For example,the cystoscope can be used to obtain visualization of the other ureteralopening in the bladder, and the guidewire can be advanced through thevisualized ureteral opening to a fluid collection position in the otherureter. A second ureteral stent or second ureteral catheter can be drawnalongside the guidewire and deployed in the manner described herein.Alternatively, the cystoscope and guidewire can be removed from thebody. The cystoscope can be reinserted into the bladder over the firstureteral catheter. The cystoscope is used, in the manner describedabove, to obtain visualization of the ureteral opening and to assist inadvancing a second guidewire to the second ureter and/or kidney forpositioning of the second ureteral stent or second ureteral catheter.Once the ureteral stents or catheters are in place, in some examples,the guidewire and cystoscope are removed. In other examples, thecystoscope and/or guidewire can remain in the bladder to assist withplacement of the bladder catheter.

In some examples, once the ureteral catheters are in place, as shown atbox 620, the medical professional, caregiver or patient can insert adistal end of a bladder catheter in a collapsed or contracted statethrough the urethra of the patient and into the bladder. The bladdercatheter can be a bladder catheter of the present invention as discussedin detail above. Once inserted in the bladder, as shown at box 622, ananchor connected to and/or associated with the bladder catheter isexpanded to a deployed position. In some examples, the bladder catheteris inserted through the urethra and into the bladder without using aguidewire and/or cystoscope. In other examples, the bladder catheter isinserted over the same guidewire used to position the ureteral stents orcatheters.

In some examples, the ureteral stent or ureteral catheter is deployedand remains in the patient's body for at least 24 hours or longer. Insome examples, the ureteral stent or ureteral catheter is deployed andremains in the patient's body for at least 30 days or longer. In someexamples, the ureteral stent(s) or ureteral catheter(s) can be replacedperiodically, for example every week or every month, to extend thelength of therapy.

In some examples, the bladder catheter is replaced more often that theureteral stent or ureteral catheter. In some examples, multiple bladdercatheters are placed and removed sequentially during the indwell timefor a single ureteral stent or ureteral catheter. For example, aphysician, nurse, caregiver or patient can place the bladder catheter(s)in the patient at home or in any healthcare setting. Multiple bladdercatheters can be provided to the healthcare professional, patient orcaregiver in a kit, optionally with instructions for placement,replacement and optional connection of the bladder catheter(s) to thenegative pressure source or drainage to a container, as needed. In someexamples, negative pressure is applied each evening for a predeterminednumber of evenings (such as for 1 to 30 evenings or more). Optionally,the bladder catheter can be replaced each evening before application ofnegative pressure.

In some examples, the urine is permitted to drain by gravity orperistalsis from the urethra. In other examples, a negative pressure isinduced in the bladder catheter to facilitate drainage of the urine.While not intending to be bound by any theory, it is believed that aportion of the negative pressure applied to the proximal end of thebladder catheter is transmitted to the ureter(s), renal pelvis or otherportions of the kidney(s) to facilitate drainage of the fluid or urinefrom the kidney.

With reference to FIG. 42B, steps for using the system for inducement ofnegative pressure in the ureter(s) and/or kidney(s) are illustrated. Asshown at box 624, after the indwelling portions of the ureteral stentsor ureteral catheters and bladder catheters are correctly positioned andany anchoring/retention structures, if present, are deployed, theexternal proximal end of the bladder catheter is connected to a fluidcollection or pump assembly. For example, the bladder catheter can beconnected to a pump for inducing negative pressure at the patient'sbladder, renal pelvis and/or kidney.

Once the bladder catheter and pump assembly are connected, negativepressure is applied to the renal pelvis and/or kidney and/or bladderthrough the drainage lumen of the bladder catheter, as shown at box 626.The negative pressure is intended to counter congestion mediatedinterstitial hydrostatic pressures due to elevated intra-abdominalpressure and consequential or elevated renal venous pressure or renallymphatic pressure. The applied negative pressure is therefore capableof increasing flow of filtrate through the medullary tubules and ofdecreasing water and sodium re-absorption.

As a result of the applied negative pressure, as shown at box 628, urineis drawn into the bladder catheter at the drainage port(s) at the distalend thereof, through the drainage lumen of the bladder catheter, and toa fluid collection container for disposal. As the urine is being drawnto the collection container, at box 630, optional sensors disposed inthe fluid collection system can provide a number of measurements aboutthe urine that can be used to assess physical parameters, such as thevolume of urine collected, as well as information about the physicalcondition of the patient and composition of the urine produced. In someexamples, the information obtained by the sensors is processed, as shownat box 632, by a processor associated with the pump and/or with anotherpatient monitoring device and, at box 634, is displayed to the user viaa visual display of an associated feedback device.

Exemplary Fluid Collection System:

Having described an exemplary system and method of positioning such asystem in the patient's body, with reference to FIG. 44, a system 700for inducing negative pressure to a patient's bladder, ureter(s), renalpelvis and/or kidney(s) will now be described. The system 700 cancomprise the ureteral stent(s) and/or ureteral catheter(s), bladdercatheter or the system 100 described hereinabove. As shown in FIG. 44,the bladder catheter 116 of the system 100 is connected to one or morefluid collection containers 712 for collecting urine drawn from thebladder. The fluid collection container 712 connected to the bladdercatheter 116 can be in fluid communication with an external fluid pump710 for generating negative pressure in the bladder, ureter(s) and/orkidney(s) through the bladder catheter 116 and/or ureteral catheter(s)112, 114. As discussed herein, such negative pressure can be providedfor overcoming interstitial pressure and forming urine in the kidney ornephron. In some examples, a connection between the fluid collectioncontainer 712 and pump 710 can comprise a fluid lock or fluid barrier toprevent air from entering the bladder, renal pelvis or kidney in case ofincidental therapeutic or non-therapeutic pressure changes. For example,inflow and outflow ports of the fluid container can be positioned belowa fluid level in the container. Accordingly, air is prevented fromentering medical tubing or the catheter through either the inflow oroutflow ports of the fluid container 712. As discussed previously,external portions of the tubing extending between the fluid collectioncontainer 712 and the pump 710 can include one or more filters toprevent urine and/or particulates from entering the pump 710.

As shown in FIG. 44, the system 700 further comprises a controller 714,such as a microprocessor, electronically coupled to the pump 710 andhaving or associated with computer readable memory 716. In someexamples, the memory 716 comprises instructions that, when executed,cause the controller 714 to receive information from sensors 174 locatedon or associated with portions of the assembly 100. Information about acondition of the patient can be determined based on information from thesensors 174. Information from the sensors 174 can also be used todetermine and implement operating parameters for the pump 710.

In some examples, the controller 714 is incorporated in a separate andremote electronic device in communication with the pump 710, such as adedicated electronic device, computer, tablet PC, or smart phone.Alternatively, the controller 714 can be included in the pump 710 and,for example, can control both a user interface for manually operatingthe pump 710, as well as system functions such as receiving andprocessing information from the sensors 174.

The controller 714 is configured to receive information from the one ormore sensors 174 and to store the information in the associatedcomputer-readable memory 716. For example, the controller 714 can beconfigured to receive information from the sensor 174 at a predeterminedrate, such as once every second, and to determine a conductance based onthe received information. In some examples, the algorithm forcalculating conductance can also include other sensor measurements, suchas urine temperature, to obtain a more robust determination ofconductance.

The controller 714 can also be configured to calculate patient physicalstatistics or diagnostic indicators that illustrate changes in thepatient's condition over time. For example, the system 700 can beconfigured to identify an amount of total sodium excreted. The totalsodium excreted may be based, for example, on a combination of flow rateand conductance over a period of time.

With continued reference to FIG. 44, the system 700 can further comprisea feedback device 720, such as a visual display or audio system, forproviding information to the user. In some examples, the feedback device720 can be integrally formed with the pump 710. Alternatively, thefeedback device 720 can be a separate dedicated or a multipurposeelectronic device, such as a computer, laptop computer, tablet PC, smartphone, or other handheld electronic devices. The feedback device 720 isconfigured to receive the calculated or determined measurements from thecontroller 714 and to present the received information to a user via thefeedback device 720. For example, the feedback device 720 may beconfigured to display current negative pressure (in mmHg) being appliedto the urinary tract. In other examples, the feedback device 720 isconfigured to display current flow rate of urine, temperature, currentconductance in mS/m of urine, total urine produced during the session,total sodium excreted during the session, other physical parameters, orany combination thereof.

In some examples, the feedback device 720 further comprises a userinterface module or component that allows the user to control operationof the pump 710. For example, the user can engage or turn off the pump710 via the user interface. The user can also adjust pressure applied bythe pump 710 to achieve a greater magnitude or rate of sodium excretionand fluid removal.

Optionally, the feedback device 720 and/or pump 710 further comprise adata transmitter 722 for sending information from the device 720 and/orpump 710 to other electronic devices or computer networks. The datatransmitter 722 can utilize a short-range or long-range datacommunications protocol. An example of a short-range data transmissionprotocol is Bluetooth®. Long-range data transmission networks include,for example, Wi-Fi or cellular networks. The data transmitter 722 cansend information to a patient's physician or caregiver to inform thephysician or caregiver about the patient's current condition.Alternatively, or in addition, information can be sent from the datatransmitter 722 to existing databases or information storage locations,such as, for example, to include the recorded information in a patient'selectronic health record (EHR).

With continued reference to FIG. 44, in addition to the urine sensors174, in some examples, the system 700 can further comprise one or morepatient monitoring sensors 724. Patient monitoring sensors 724 caninclude invasive and non-invasive sensors for measuring informationabout the patient's physical parameters, such as urine composition, asdiscussed in detail above, blood composition (e.g., hematocrit ratio,analyte concentration, protein concentration, creatinine concentration)and/or blood flow (e.g., blood pressure, blood flow velocity).Hematocrit is a ratio of the volume of red blood cells to the totalvolume of blood. Normal hematocrit is about 25% to 40%, and preferablyabout 35% and 40% (e.g., 35% to 40% red blood cells by volume and 60% to65% plasma).

Non-invasive patient monitoring sensors 724 can include pulse oximetrysensors, blood pressure sensors, heart rate sensors, and respirationsensors (e.g., a capnography sensor). Invasive patient monitoringsensors 724 can include invasive blood pressure sensors, glucosesensors, blood velocity sensors, hemoglobin sensors, hematocrit sensors,protein sensors, creatinine sensors, and others. In still otherexamples, sensors may be associated with an extracorporeal blood systemor circuit and configured to measure parameters of blood passing throughtubing of the extracorporeal system. For example, analyte sensors, suchas capacitance sensors or optical spectroscopy sensors, may beassociated with tubing of the extracorporeal blood system to measureparameter values of the patient's blood as it passes through the tubing.The patient monitoring sensors 724 can be in wired or wirelesscommunication with the pump 710 and/or controller 714.

In some examples, the controller 714 is configured to cause the pump 710to provide treatment for a patient based information obtained from theurine analyte sensor 174 and/or patient monitoring sensors 724, such asblood monitoring sensors. For example, pump 710 operating parameters canbe adjusted based on changes in the patient's blood hematocrit ratio,blood protein concertation, creatinine concentration, urine outputvolume, urine protein concentration (e.g., albumin), and otherparameters. For example, the controller 714 can be configured to receiveinformation about a blood hematocrit ratio or creatinine concentrationof the patient from the patient monitoring sensors 724 and/or analytesensors 174. The controller 714 can be configured to adjust operatingparameters of the pump 710 based on the blood and/or urine measurements.In other examples, hematocrit ratio may be measured from blood samplesperiodically obtained from the patient. Results of the tests can bemanually or automatically provided to the controller 714 for processingand analysis.

As discussed herein, measured hematocrit values for the patient can becompared to predetermined threshold or clinically acceptable values forthe general population. Generally, hematocrit levels for females arelower than for males. In other examples, measured hematocrit values canbe compared to patient baseline values obtained prior to a surgicalprocedure. When the measured hematocrit value is increased to within theacceptable range, the pump 710 may be turned off ceasing application ofnegative pressure to the ureter or kidneys. In a similar manner, theintensity of negative pressure can be adjusted based on measuredparameter values. For example, as the patient's measured parametersbegin to approach the acceptable range, intensity of negative pressurebeing applied to the ureter and kidneys can be reduced. In contrast, ifan undesirable trend (e.g., a decrease in hematocrit value, urine outputrate, and/or creatinine clearance) is identified, the intensity ofnegative pressure can be increased in order to produce a positivephysiological result. For example, the pump 710 may be configured tobegin by providing a low level of negative pressure (e.g., between about0.1 mmHg and 10 mmHg). The negative pressure may be incrementallyincreased until a positive trend in patient creatinine level isobserved. However, generally, negative pressure provided by the pump 710will not exceed about 50 mmHg.

With reference to FIGS. 45A and 45B, an exemplary pump 710 for use withthe system is illustrated. In some examples, the pump 710 is amicro-pump configured to draw fluid from the catheter(s) 112, 114(shown, for example, in FIGS. 1A, 1B, 1C, 1F, 1P, 1U, 2A, 2B) and havinga sensitivity or accuracy of about 10 mm Hg or less. Desirably, the pump710 is capable of providing a range of flow of urine between 0.05 ml/minand 3 ml/min for extended periods of time, for example, for about 8hours to about 24 hours per day, for one (1) to about 30 days or longer.At 0.2 ml/min, it is anticipated that about 300 mL of urine per day iscollected by the system 700. The pump 710 can be configured to provide anegative pressure to the bladder of the patient, the negative pressureranging from about 0.1 mmHg and about 150 mmHg, or about 0.1 mmHg toabout 50 mmHg, or about 5 mmHg to about 20 mmHg (gauge pressure at thepump 710). For example, a micro-pump manufactured by Langer Inc. (ModelBT100-2J) can be used with the presently disclosed system 700. Diaphragmaspirator pumps, as well as other types of commercially available pumps,can also be used for this purpose. Peristaltic pumps can also be usedwith the system 700. In other examples, a piston pump, vacuum bottle, ormanual vacuum source can be used for providing negative pressure. Inother examples, the system can be connected to a wall suction source, asis available in a hospital, through a vacuum regulator for reducingnegative pressure to therapeutically appropriate levels.

In some examples, at least a portion of the pump assembly can bepositioned within the patient's urinary tract, for example within thebladder. For example, the pump assembly can comprise a pump module and acontrol module coupled to the pump module, the control module beingconfigured to direct motion of the pump module. At least one (one ormore) of the pump module, the control module, or the power supply may bepositioned within the patient's urinary tract. The pump module cancomprise at least one pump element positioned within the fluid flowchannel to draw fluid through the channel. Some examples of suitablepump assemblies, systems and methods of use are disclosed in U.S. PatentApplication No. 62/550,259, entitled “Indwelling Pump for FacilitatingRemoval of Urine from the Urinary Tract”, filed on Aug. 25, 2017, whichis incorporated by reference herein in its entirety.

In some examples, the pump 710 is configured for extended use and, thus,is capable of maintaining precise suction for extended periods of time,for example, for about 8 hours to about 24 hours per day, or for 1 toabout 30 days or longer, except for replacement time of bladdercatheters. Further, in some examples, the pump 710 is configured to bemanually operated and, in that case, includes a control panel 718 thatallows a user to set a desired suction value. The pump 710 can alsoinclude a controller or processor, which can be the same controller thatoperates the system 700 or can be a separate processor dedicated foroperation of the pump 710. In either case, the processor is configuredfor both receiving instructions for manual operation of the pump and forautomatically operating the pump 710 according to predeterminedoperating parameters. Alternatively, or in addition, operation of thepump 710 can be controlled by the processor based on feedback receivedfrom the plurality of sensors associated with the catheter.

In some examples, the processor is configured to cause the pump 710 tooperate intermittently. For example, the pump 710 may be configured toemit pulses of negative pressure followed by periods in which nonegative pressure is provided. In other examples, the pump 710 can beconfigured to alternate between providing negative pressure and positivepressure to produce an alternating flush and pump effect. For example, apositive pressure of about 0.1 mmHg to 20 mmHg, and preferably about 5mmHg to 20 mmHg can be provided followed by a negative pressure rangingfrom about 0.1 mmHg to 50 mmHg.

Steps for removing excess fluid from a patient using the devices andsystems described herein are illustrated in FIG. 49. As shown in FIG.49, the treatment method comprises deploying a ureteral stent or aurinary tract catheter, such as a ureteral catheter, in the ureterand/or kidney of a patient such that flow of urine from the ureterand/or kidney, as shown at box 910. The catheter may be placed to avoidoccluding the ureter and/or kidney. In some examples, a fluid collectingportion of the stent or catheter may be positioned in the renal pelvisof the patient's kidney. In some examples, a ureteral stent or ureteralcatheter may be positioned in each of the patient's kidneys. In otherexamples, a urine collection catheter may be deployed in the bladder orureter, as shown in box 911. In some examples, the ureteral cathetercomprises one or more of any of the retention portions described herein.For example, the ureteral catheter can comprise a tube defining adrainage lumen comprising a helical retention portion and a plurality ofdrainage ports. In other examples, the catheter can include afunnel-shaped fluid collection and retention portion or a pigtail coil.Alternatively, a ureteral stent, having, for example, a pigtail coil,can be deployed.

As shown at box 912, the method further comprises applying negativepressure to at least one of the bladder, the ureter and/or kidneythrough the bladder catheter to induce or facilitate production of fluidor urine in the kidney(s) and to extract the fluid or urine from thepatient. Desirably, negative pressure is applied for a period of timesufficient to reduce the patient's blood creatinine levels by aclinically significant amount.

Negative pressure may continue to be applied for a predetermined periodof time. For example, a user may be instructed to operate the pump forthe duration of a surgical procedure or for a time period selected basedon physiological characteristics of the patient. In other examples,patient condition may be monitored to determine when sufficienttreatment has been provided. For example, as shown at box 914, themethod may further comprise monitoring the patient to determine when tocease applying negative pressure to the patient's bladder, ureter and/orkidneys. In some examples, a patient's hematocrit level is measured. Forexample, patient monitoring devices may be used to periodically obtainhematocrit values. In other examples, blood samples may be drawnperiodically to directly measure hematocrit. In some examples,concentration and/or volume of urine expelled from the body through thebladder catheter may be monitored to determine a rate at which urine isbeing produced by the kidneys. In a similar manner, expelled urineoutput may be monitored to determine protein concentration and/orcreatinine clearance rate for the patient. Reduced creatinine andprotein concentration in urine may be indicative of over-dilution and/ordepressed renal function. Measured values can be compared to thepredetermined threshold values to assess whether negative pressuretherapy is improving patient condition, and should be modified ordiscontinued. For example, as discussed herein, a desirable range forpatient hematocrit may be between 25% and 40%. In other examples, asdescribed herein, patient body weight may be measured and compared to adry body weight. Changes in measured patient body weight demonstratethat fluid is being removed from the body. As such, a return to dry bodyweight represents that hemodilution has been appropriately managed andthe patient is not over-diluted.

As shown at box 916, a user may cause the pump to cease providingnegative pressure therapy when a positive result is identified. In asimilar manner, patient blood parameters may be monitored to assesseffectiveness of the negative pressure being applied to the patient'skidneys. For example, a capacitance or analyte sensor may be placed influid communication with tubing of an extracorporeal blood managementsystem. The sensor may be used to measure information representative ofblood protein, oxygen, creatinine, and/or hematocrit levels. Measuredblood parameter values may be measured continuously or periodically andcompared to various threshold or clinically acceptable values. Negativepressure may continue to be applied to the patient's bladder, kidney orureter until a measured parameter value falls within a clinicallyacceptable range. Once a measured values fails within the threshold orclinically acceptable range, as shown at box 916, application ofnegative pressure may cease.

In some examples, there is provided a method of removing excess fluidfrom a patient for systemic fluid volume management associated withchronic edematous, hypertension, chronic kidney disease and/or acuteheart failure. According to another aspect of the disclosure, a methodfor removing excess fluid for a patient undergoing a fluid resuscitationprocedure, such as coronary graft bypass surgery, by removing excessfluid from the patient is provided. During fluid resuscitation,solutions such as saline solutions and/or starch solutions, areintroduced to the patient's bloodstream by a suitable fluid deliveryprocess, such as an intravenous drip. For example, in some surgicalprocedures, a patient may be supplied with between 5 and 10 times anormal daily intake of fluid. Fluid replacement or fluid resuscitationcan be provided to replace bodily fluids lost through sweating,bleeding, dehydration, and similar processes. In the case of a surgicalprocedure such as coronary graft bypass, fluid resuscitation is providedto help maintain a patient's fluid balance and blood pressure within anappropriate rate. Acute kidney injury (AKI) is a known complication ofcoronary artery graft bypass surgery. AKI is associated with a prolongedhospital stay and increased morbidity and mortality, even for patientswho do not progress to renal failure. See Kim, et al., Relationshipbetween a perioperative intravenous fluid administration strategy andacute kidney injury following off-pump coronary artery bypass surgery:an observational study, Critical Care 19:350 (1995). Introducing fluidto blood also reduces hematocrit levels which has been shown to furtherincrease mortality and morbidity. Research has also demonstrated thatintroducing saline solution to a patient may depress renal functionaland/or inhibit natural fluid management processes. As such, appropriatemonitoring and control of renal function may produce improved outcomesand, in particular, may reduce post-operative instances of AKI.

A method of treating a patient for removing excess fluid is illustratedin FIG. 50. As shown at box 1010, the method comprises deploying aureteral stent or ureteral catheter in the ureter and/or kidney of apatient such that flow of urine from the ureter and/or kidney is notprevented by occlusion of the ureter and/or kidney. For example, adistal end of the ureteral stent or fluid collecting portion of thecatheter may be positioned in the renal pelvis. In other examples, thecatheter may be deployed in the kidney or ureter. The catheter cancomprise one or more of the ureter catheters described herein. Forexample, the catheter can comprise a tube defining a drainage lumen andcomprising a helical retention portion and a plurality of drainageports. In other examples, the catheter can include a pigtail coil.

As shown at box 1012, a bladder catheter can be deployed in thepatient's bladder. For example, the bladder catheter may be positionedto at least partially seal the urethra opening to prevent passage ofurine from the body through the urethra. The bladder catheter can, forexample, include an anchor for maintaining the distal end of thecatheter in the bladder. As described herein, other arrangements ofcoils and helices, funnel, etc. may be used to obtain proper positioningof the bladder catheter. The bladder catheter can be configured tocollect fluid which entered the patient's bladder prior to placement ofthe ureteral catheter(s), as well as fluid collected from the ureters,ureteral stents, and/or ureteral catheters during treatment. The bladdercatheter may also collect urine which flows past the fluid collectionportion(s) of the ureteral catheter and enters the bladder. In someexamples, a proximal portion of the ureteral catheter may be positionedin a drainage lumen of the bladder catheter. In a similar manner, thebladder catheter may be advanced into the bladder using the sameguidewire used for positioning of the ureteral catheter(s). In someexamples, negative pressure may be provided to the bladder through thedrainage lumen of the bladder catheter. In other examples, negativepressure may only be applied to the bladder catheter(s). In that case,the ureteral catheter drains into the bladder by gravity.

As shown at box 1014, following deployment of the ureteral stents and/orureteral catheter(s) and the bladder catheter, negative pressure isapplied to the bladder, ureter and/or kidney through the bladdercatheter. For example, negative pressure can be applied for a period oftime sufficient to extract urine comprising a portion of the fluidprovided to the patient during the fluid resuscitation procedure. Asdescribed herein, negative pressure can be provided by an external pumpconnected to a proximal end or port of the bladder catheter. The pumpcan be operated continually or periodically dependent on therapeuticrequirements of the patient. In some cases, the pump may alternatebetween applying negative pressure and positive pressure.

Negative pressure may continue to be applied for a predetermined periodof time. For example, a user may be instructed to operate the pump forthe duration of a surgical procedure or for a time period selected basedon physiological characteristics of the patient. In other examples,patient condition may be monitored to determine when a sufficient amountof fluid has been drawn from the patient. For example, as shown at box1016, fluid expelled from the body may be collected and a total volumeof obtained fluid may be monitored. In that case, the pump can continueto operate until a predetermined fluid volume has been collected fromthe ureteral and/or bladder catheters. The predetermined fluid volumemay be based, for example, on a volume of fluid provided to the patientprior to and during the surgical procedure. As shown at box 1018,application of negative pressure to the bladder, ureter and/or kidneysis stopped when the collected total volume of fluid exceeds thepredetermined fluid volume.

In other examples, operation of the pump can be determined based onmeasured physiological parameters of the patient, such as measuredcreatinine clearance, blood creatinine level, or hematocrit ratio. Forexample, as shown at box 1020, urine collected form the patient may beanalyzed by one or more sensors associated with the catheter and/orpump. The sensor can be a capacitance sensor, analyte sensor, opticalsensor, or similar device configured to measure urine analyteconcentration. In a similar manner, as shown at box 1022, a patient'sblood creatinine or hematocrit level could be analyzed based oninformation obtain from the patient monitoring sensors discussedhereinabove. For example, a capacitance sensor may be placed in anexisting extracorporeal blood system. Information obtained by thecapacitance sensor may be analyzed to determine a patient's hematocritratio. The measured hematocrit ratio may be compared to certain expectedor therapeutically acceptable values. The pump may continue to applynegative pressure to the patient's ureter and/or kidney until measuredvalues within the therapeutically acceptable range are obtained. Once atherapeutically acceptable value is obtained, application of negativepressure may be stopped as shown at box 1018.

In other examples, as shown at box 2024, patient body weight may bemeasured to assess whether fluid is being removed from the patient bythe applied negative pressure therapy. For example, a patient's measuredbodyweight (including fluid introduced during a fluid resuscitationprocedure) can be compared to a patient's dry body weight. As usedherein, dry weights is defined as normal body weight measured when apatient is not over-diluted. For example, a patient who is notexperiencing one or more of: elevated blood pressure, lightheadedness orcramping, swelling of legs, feet, arms, hands, or around the eyes, andwho is breathing comfortably, likely does not have excess fluid. Aweight measured when the patient is not experiencing such symptoms canbe a dry body weight. Patient weight can be measured periodically untilthe measured weight approaches the dry body weight. When the measuredweight approaches (e.g., is within between 5% and 10% of dry bodyweight), as shown at box 1018, application of negative pressure can bestopped.

The aforementioned details of treatment using the systems of the presentinvention can be used to treat a variety of conditions that can benefitfrom increased urine or fluid output or removal. For example, a methodfor preserving renal function by application of negative pressure todecrease interstitial pressure within tubules of the medullar region tofacilitate urine output and to prevent venous congestion-induced nephronhypoxia in the medulla of the kidney is provided. The method comprises:deploying a ureteral stent or ureteral catheter into a ureter or kidneyof a patient to maintain patency of fluid flow between a kidney and abladder of the patient; deploying a bladder catheter into the bladder ofthe patient, wherein the bladder catheter comprises a distal endconfigured to be positioned in a patient's bladder, a drainage lumenportion having a proximal end, and a sidewall extending therebetween;and applying negative pressure to the proximal end of the catheter toinduce negative pressure in a portion of the urinary tract of thepatient for a predetermined period of time to remove fluid from theurinary tract of the patient.

In another example, a method for treatment of acute kidney injury due tovenous congestion is provided. The method comprises: deploying aureteral stent or ureteral catheter into a ureter or kidney of a patientto maintain patency of fluid flow between a kidney and a bladder of thepatient; deploying a bladder catheter into the bladder of the patient,wherein the bladder catheter comprises a distal end configured to bepositioned in a patient's bladder, a drainage lumen portion having aproximal end, and a sidewall extending therebetween; and applyingnegative pressure to the proximal end of the catheter to induce negativepressure in a portion of the urinary tract of the patient for apredetermined period of time to remove fluid from the urinary tract ofthe patient, thereby reducing venous congestion in the kidney to treatacute kidney injury.

In another example, a method for treatment of New York Heart Association(NYHA) Class III and/or Class IV heart failure through reduction ofvenous congestion in the kidney(s) is provided. The method comprises:deploying a ureteral stent or ureteral catheter into a ureter or kidneyof a patient to maintain patency of fluid flow between a kidney and abladder of the patient; deploying a bladder catheter into the bladder ofthe patient, wherein the bladder catheter comprises a distal endconfigured to be positioned in a patient's bladder, a drainage lumenportion having a proximal end, and a sidewall extending therebetween;and applying negative pressure to the proximal end of the catheter toinduce negative pressure in a portion of the urinary tract of thepatient for a predetermined period of time to remove fluid from theurinary tract of the patient to treat volume overload in NYHA Class IIIand/or Class IV heart failure.

In another example, a method for treatment of Stage 4 and/or Stage 5chronic kidney disease through reduction of venous congestion in thekidney(s) is provided. The method comprises: deploying a ureteral stentor ureteral catheter into a ureter or kidney of a patient to maintainpatency of fluid flow between a kidney and a bladder of the patient;deploying a bladder catheter into the bladder of the patient, whereinthe bladder catheter comprises a distal end configured to be positionedin a patient's bladder, a drainage lumen portion having a proximal end,and a sidewall extending therebetween; and applying negative pressure tothe proximal end of the catheter to induce negative pressure in aportion of the urinary tract of the patient to remove fluid from theurinary tract of the patient to reduce venous congestion in thekidney(s).

In some examples, a kit is provided for removing fluid from the urinarytract of a patient and/or inducing negative pressure in a portion of aurinary tract of a patient. The kit comprises: a ureteral stent orureteral catheter comprising a drainage channel for facilitating flow offluid from the ureter and/or kidney through the drainage channel of theureteral stent or ureteral catheter towards the bladder of the patient;and a pump comprising a controller configured to induce a negativepressure in at least one of the ureter, kidney or bladder of the patientto draw urine through a drainage lumen of a catheter deployed in thepatient's bladder. In some examples, the kit further comprises at leastone bladder catheter. In some examples, the kit further comprisesinstructions for one or more of the following: inserting/deploying theureteral stent(s) and/or ureteral catheter(s), inserting/deploying thebladder catheter, and operating the pump to draw urine through adrainage lumen of the bladder catheter deployed the patient's bladder.

In some examples, another kit comprises: a plurality of disposablebladder catheters, each bladder catheter comprising a drainage lumenportion having a proximal end, a distal end configured to be positionedin a patient's bladder, and a sidewall extending therebetween; and aretention portion extending radially outward from a portion of thedistal end of the drainage lumen portion, and being configured to beextended into a deployed position in which a diameter of the retentionportion is greater than a diameter of the drainage lumen portion;instructions for inserting/deploying the bladder catheter; andinstructions for connecting the proximal end of the bladder catheter toa pump and for operating the pump to draw urine through the drainagelumen of the bladder catheter, for example by applying negative pressureto the proximal end of the bladder catheter.

In some examples, a kit is provided, the kit comprising: a plurality ofdisposable bladder catheters, each bladder catheter comprising (a) aproximal portion; and (b) a distal portion, the distal portioncomprising a retention portion that comprises one or more protecteddrainage holes, ports or perforations and is configured to establish anouter periphery or protective surface area that inhibits mucosal tissuefrom occluding the one or more protected drainage holes, ports orperforations upon application of negative pressure through the catheter;instructions for deploying the bladder catheter; and instructions forconnecting the proximal end of the bladder catheter to a pump and foroperating the pump to draw urine through the drainage lumen of thebladder catheter.

EXPERIMENTAL EXAMPLES OF INDUCING NEGATIVE PRESSURE USING URETERALCATHETERS

Inducement of negative pressure within the renal pelvis of farm swinewas performed for the purpose of evaluating effects of negative pressuretherapy on renal congestion in the kidney. An objective of these studieswas to demonstrate whether a negative pressure delivered into the renalpelvis significantly increases urine output in a swine model of renalcongestion. In Example 1, a pediatric Fogarty catheter, normally used inembolectomy or bronchoscopy applications, was used in the swine modelsolely for proof of principle for inducement of negative pressure in therenal pelvis. It is not suggested that a Fogarty catheter be used inhumans in clinical settings to avoid injury of urinary tract tissues. InExample 2, the ureteral catheter 112 shown in FIGS. 2A and 2B, andincluding a helical retention portion for mounting or maintaining adistal portion of the catheter in the renal pelvis or kidney, was used.

Example 1

Method

Four farm swine 800 were used for purposes of evaluating effects ofnegative pressure therapy on renal congestion in the kidney. As shown inFIG. 21, pediatric Fogarty catheters 812, 814 were inserted to the renalpelvis region 820, 821 of each kidney 802, 804 of the four swine 800.The catheters 812, 814 were deployed within the renal pelvis region byinflating an expandable balloon to a size sufficient to seal the renalpelvis and to maintain the position of the balloon within the renalpelvis. The catheters 812, 814 extend from the renal pelvis 802, 804,through a bladder 810 and urethra 816, and to fluid collectioncontainers external to the swine.

Urine output of two animals was collected for a 15 minute period toestablish a baseline for urine output volume and rate. Urine output ofthe right kidney 802 and the left kidney 804 were measured individuallyand found to vary considerably. Creatinine clearance values were alsodetermined.

Renal congestion (e.g., congestion or reduced blood flow in the veins ofthe kidney) was induced in the right kidney 802 and the left kidney 804of the animal 800 by partially occluding the inferior vena cava (IVC)with an inflatable balloon catheter 850 just above to the renal veinoutflow. Pressure sensors were used to measure IVC pressure. Normal IVCpressures were 1-4 mmHg. By inflating the balloon of the catheter 850 toapproximately three quarters of the IVC diameter, the IVC pressures wereelevated to between 15-25 mmHg. Inflation of the balloon toapproximately three quarters of IVC diameter resulted in a 50-85%reduction in urine output. Full occlusion generated IVC pressures above28 mmHg and was associated with at least a 95% reduction in urineoutput.

One kidney of each animal 800 was not treated and served as a control(“the control kidney 802”). The ureteral catheter 812 extending from thecontrol kidney was connected to a fluid collection container 819 fordetermining fluid levels. One kidney (“the treated kidney 804”) of eachanimal was treated with negative pressure from a negative pressuresource (e.g., a therapy pump 818 in combination with a regulatordesigned to more accurately control the low magnitude of negativepressures) connected to the ureteral catheter 814. The pump 818 was anAir Cadet Vacuum Pump from Cole-Parmer Instrument Company (Model No.EW-07530-85). The pump 818 was connected in series to the regulator. Theregulator was an V-800 Series Miniature Precision Vacuum Regulator—1/8NPT Ports (Model No. V-800-10-W/K), manufactured by Airtrol ComponentsInc.

The pump 818 was actuated to induce negative pressure within the renalpelvis 820, 821 of the treated kidney according to the followingprotocol. First, the effect of negative pressure was investigated in thenormal state (e.g., without inflating the IVC balloon). Four differentpressure levels (−2, −10, −15, and −20 mmHg) were applied for 15 minuteseach and the rate of urine produced and creatinine clearance weredetermined. Pressure levels were controlled and determined at theregulator. Following the −20 mmHg therapy, the IVC balloon was inflatedto increase the pressure by 15-20 mmHg. The same four negative pressurelevels were applied. Urine output rate and creatinine clearance rate forthe congested control kidney 802 and treated kidney 804 were obtained.The animals 800 were subject to congestion by partial occlusion of theIVC for 90 minutes. Treatment was provided for 60 minutes of the 90minute congestion period.

Following collection of urine output and creatinine clearance data,kidneys from one animal were subjected to gross examination then fixedin a 10% neutral buffered formalin. Following gross examination,histological sections were obtained, examined, and magnified images ofthe sections were captured. The sections were examined using an uprightOlympus BX41 light microscope and images were captured using an OlympusDP25 digital camera. Specifically, photomicrograph images of the sampledtissues were obtained at low magnification (20× original magnification)and high magnification (100× original magnification). The obtainedimages were subjected to histological evaluation. The purpose of theevaluation was to examine the tissue histologically and to qualitativelycharacterize congestion and tubular degeneration for the obtainedsamples.

Surface mapping analysis was also performed on obtained slides of thekidney tissue. Specifically, the samples were stained and analyzed toevaluate differences in size of tubules for treated and untreatedkidneys. Image processing techniques calculated a number and/or relativepercentage of pixels with different coloration in the stained images.Calculated measurement data was used to determine volumes of differentanatomical structures.

Results

Urine Output and Creatinine Clearance

Urine output rates were highly variable. Three sources of variation inurine output rate were observed during the study. The inter-individualand hemodynamic variability were anticipated sources of variabilityknown in the art. A third source of variation in urine output, uponinformation and belief believed to be previously unknown, was identifiedin the experiments discussed herein, namely, contralateralintra-individual variability in urine output.

Baseline urine output rates were 0.79 ml/min for one kidney and 1.07ml/min for the other kidney (e.g., a 26% difference). The urine outputrate is a mean rate calculated from urine output rates for each animal.

When congestion was provided by inflating the IVC balloon, the treatedkidney urine output dropped from 0.79 ml/min to 0.12 ml/min (15.2% ofbaseline). In comparison, the control kidney urine output rate duringcongestion dropped from 1.07 ml/min to 0.09 ml/min (8.4% of baseline).Based on urine output rates, a relative increase in treated kidney urineoutput compared to control kidney urine output was calculated, accordingto the following equation:

(Therapy  Treated/Baseline  Treated)/(Therapy  Control/Baseline  Control) = Relative  increase  (0.12  ml/min /0.79  ml/min )/(0.09  ml/min  /1.07  ml/min ) = 180.6%

Thus, the relative increase in treated kidney urine output rate was180.6% compared to control. This result shows a greater magnitude ofdecrease in urine production caused by congestion on the control sidewhen compared to the treatment side. Presenting results as a relativepercentage difference in urine output adjusts for differences in urineoutput between kidneys.

Creatinine clearance measurements for baseline, congested, and treatedportions for one of the animals are shown in FIG. 22.

Gross Examination and Histological Evaluation

Based on gross examination of the control kidney (right kidney) andtreated kidney (left kidney), it was determined that the control kidneyhad a uniformly dark red-brown color, which corresponds with morecongestion in the control kidney compared to the treated kidney.Qualitative evaluation of the magnified section images also notedincreased congestion in the control kidney compared to the treatedkidney. Specifically, as shown in Table 1, the treated kidney exhibitedlower levels of congestion and tubular degeneration compared to thecontrol kidney. The following qualitative scale was used for evaluationof the obtained slides.

Congestion

Lesion Score None: 0 Mild: 1 Moderate: 2 Marked: 3 Severe: 4

Tubular Degeneration:

Lesion Score None: 0 Mild: 1 Moderate: 2 Marked: 3 Severe: 4

TABLE 1 TABULATED RESULTS Histologic lesions Tubular Animal ID/Organ/Slide hyaline Gross lesion number Congestion casts Granulomas 6343/LeftKidney/ R16-513-1 1 1 0 Normal 6343/Left Kidney/ R16-513-2 1 1 0 Normalwith hemorrhagic streak 6343/Right Kidney/ R16-513-3 2 2 1 Congestion6343/Right Kidney/ R16-513-4 2 1 1 Congestion

As shown in Table 1, the treated kidney (left kidney) exhibited onlymild congestion and tubular degeneration. In contrast, the controlkidney (right kidney) exhibited moderate congestion and tubulardegeneration. These results were obtained by analysis of the slidesdiscussed below.

FIGS. 48A and 48B are low and high magnification photomicrographs of theleft kidney (treated with negative pressure) of the animal. Based on thehistological review, mild congestion in the blood vessels at thecorticomedullary junction was identified, as indicated by the arrows. Asshown in FIG. 48B, a single tubule with a hyaline cast (as identified bythe asterisk) was identified.

FIGS. 48C and 48D are low and high resolution photomicrographs of thecontrol kidney (right kidney). Based on the histological review,moderate congestion in the blood vessel at the corticomedullary junctionwas identified, as shown by the arrows in FIG. 48C. As shown in FIG.48D, several tubules with hyaline casts were present in the tissuesample (as identified by asterisks in the image). Presence of asubstantial number of hyaline casts is evidence of hypoxia.

Surface mapping analysis provided the following results. The treatedkidney was determined to have 1.5 times greater fluid volume in Bowman'sspace and 2 times greater fluid volume in tubule lumen. Increased fluidvolume in Bowman's space and the tubule lumen corresponds to increasedurine output. In addition, the treated kidney was determined to have 5times less blood volume in capillaries compared to the control kidney.The increased volume in the treated kidney appears to be a result of (1)a decrease in individual capillary size compared to the control and (2)an increase in the number of capillaries without visible red blood cellsin the treated kidney compared to the control kidney, an indicator ofless congestion in the treated organ.

Summary

These results indicate that the control kidney had more congestion andmore tubules with intraluminal hyaline casts, which representprotein-rich intraluminal material, compared to the treated kidney.Accordingly, the treated kidney exhibits a lower degree of loss of renalfunction. While not intending to be bound by theory, it is believed thatas severe congestion develops in the kidney, hypoxemia of the organfollows. Hypoxemia interferes with oxidative phosphorylation within theorgan (e.g., ATP production). Loss of ATP and/or a decrease in ATPproduction inhibits the active transport of proteins causingintraluminal protein content to increase, which manifests as hyalinecasts. The number of renal tubules with intraluminal hyaline castscorrelates with the degree of loss of renal function. Accordingly, thereduced number of tubules in the treated left kidney is believed to bephysiologically significant. While not intending to be bound by theory,it is believed that these results show that damage to the kidney can beprevented or inhibited by applying negative pressure to a ureteralcatheter inserted into the renal pelvis to facilitate urine output.

Example 2

Method

Four (4) farm swine (A, B, C, D) were sedated and anesthetized. Vitalsfor each of the swine were monitored throughout the experiment andcardiac output was measured at the end of each 30-minute phase of thestudy. Ureteral catheters, such as the ureteral catheter 112 shown inFIGS. 2A and 2B, were deployed in the renal pelvis region of the kidneysof each of the swine. The deployed catheters were a 6 Fr catheter havingan outer diameter of 2.0±0.1 mm. The catheters were 54±2 cm in length,not including the distal retention portion. The retention portion was16±2 mm in length. As shown in the catheter 112 in FIGS. 2A and 2B, theretention portion included two full coils and one proximal half coil.The outer diameter of the full coils, shown by line D1 in FIGS. 2A and2B, was 18±2 mm. The half coil diameter D2 was about 14 mm. Theretention portion of the deployed ureteral catheters included sixdrainage openings, plus an additional opening at the distal end of thecatheter tube. The diameter of each of the drainage openings was0.83±0.01 mm. The distance between adjacent drainage openings 132,specifically the linear distance between drainage openings when thecoils were straightened, was 22.5±2.5 mm.

The ureteral catheters were positioned to extend from the renal pelvisof the swine, through the bladder, and urethra, and to fluid collectioncontainers external to each swine. Following placement of the ureteralcatheters, pressure sensors for measuring IVC pressure were placed inthe IVC at a position distal to the renal veins. An inflatable ballooncatheter, specifically a PTS® percutaneous balloon catheter (30 mmdiameter by 5 cm length), manufactured by NuMED Inc. of Hopkinton, N.Y.,was expanded in the IVC at a position proximal to the renal veins. Athermodilution catheter, specifically a Swan-Ganz thermodilutionpulmonary artery catheter manufactured by Edwards Lifesciences Corp. ofIrvine, Calif., was then placed in the pulmonary artery for the purposeof measuring cardiac output.

Initially, baseline urine output was measured for 30 minutes, and bloodand urine samples were collected for biochemical analysis. Following the30-minute baseline period, the balloon catheter was inflated to increaseIVC pressure from a baseline pressure of 1-4 mmHg to an elevatedcongested pressure of about 20 mmHg (+/−5 mmHg). A congestion baselinewas then collected for 30 minutes with corresponding blood and urineanalysis.

At the end of the congestion period, the elevated congested IVC pressurewas maintained and negative pressure diuresis treatment was provided forswine A and swine C. Specifically, the swine (A, C) were treated byapplying a negative pressure of −25 mmHg through the ureteral catheterswith a pump. As in previously-discussed examples, the pump was an AirCadet Vacuum Pump from Cole-Parmer Instrument Company (Model No.EW-07530-85). The pump was connected in series to a regulator. Theregulator was a V-800 Series Miniature Precision Vacuum Regulator—1/8NPT Ports (Model No. V-800-10-W/K), manufactured by Airtrol ComponentsInc. The swine were observed for 120 minutes, as treatment was provided.Blood and urine collection were performed every 30 minutes, during thetreatment period. Two of the swine (B, D) were treated as congestedcontrols (e.g., negative pressure was not applied to the renal pelvisthrough the ureteral catheters), meaning that the two swine (B, D) didnot receive negative pressure diuresis therapy.

Following collection of urine output and creatinine clearance data forthe 120-minute treatment period, the animals were sacrificed and kidneysfrom each animal were subjected to gross examination. Following grossexamination, histological sections were obtained and examined, andmagnified images of the sections were captured.

Results

Measurements collected during the Baseline, Congestion, and Treatmentperiods are provided in Table 2. Specifically, urine output, serumcreatinine, and urinary creatinine measurements were obtained for eachtime period. These values allow for the calculation of a measuredcreatinine clearance as follows:

${{Creatinine}\mspace{14mu}{Clearance}\text{:}\mspace{14mu}{CrCl}} = {{Urine}\mspace{14mu}{{Output}\left( {{ml}\text{/}\min} \right)}*\frac{{Urinary}\mspace{14mu}{{Creatinine}\left( {{mg}\text{/}{dl}} \right)}}{{Serum}\mspace{14mu}{{Creatinine}\left( {{mg}\text{/}{dl}} \right)}}}$In addition, Neutrophil gelatinase-associated lipocalin (NGAL) valueswere measured from serum samples obtained for each time period andKidney Injury Molecule 1 (KIM-1) values were measured from the urinesamples obtained for each time period. Qualitative histological findingsdetermined from review of the obtained histological sections are alsoincluded in Table 2.

TABLE 2 Animal A B C D Treatment assignment Treatment Control TreatmentControl Baseline: Urine output (ml/min) 3.01 2.63 0.47 0.98 Serumcreatinine (mg/dl) 0.8 0.9 3.2 1.0 Creatinine clearance (ml/min) 261 1725.4 46.8 Serum NGAL (ng/ml) 169 * 963 99 Urinary KIM-1 (ng/ml) 4.11 *3.59 1.16 Congestion: Urine output (ml/min) 0.06 (2%) 0.53 (20%) 0.12(25%) 0.24 (25%) Serum creatinine (mg/dl) 1.2 (150%) 1.1 (122%) 3.1(97%) 1.2 (120%) Creatinine clearance (ml/min) 1.0 (0.4%) 30.8 (18%) 1.6(21%) 16.2 (35%) Serum NGAL (ng/ml) 102 (60%) * 809 (84%) 126 (127%)Urinary KIM-1 (ng/ml) 24.3 (591%) * 2.2 (61%) 1.39 (120%) Treatment:Urine output (ml/min) 0.54 (17%) ** 0.47 (101%) 0.35 (36%) Serumcreatinine (mg/dl) 1.3 (163%) 3.1 (97%) 1.7 (170%) Creatinine clearance(ml/min) 30.6 (12%) 18.3 (341%) 13.6 (29%) Serum NGAL (ng/ml) 197 (117%)1104 (115%) 208 (209%) Urinary KIM-1 (ng/ml) 260 (6326%) 28.7 (799%) 233(20000%) Histological findings: Blood volume in capillary space 2.4% **0.9% 4.0% Hyaline casts Mild/Mod None Mod Degranulation Mild/Mod NoneMod Data are raw values (% baseline) * not measured ** confounded byphenylephrine

Animal A: The animal weighed 50.6 kg and had a baseline urine outputrate of 3.01 ml/min, a baseline serum creatinine of 0.8 mg/dl, and ameasured CrCl of 261 ml/min. It is noted that these measurements, asidefrom serum creatinine, were uncharacteristically high relative to otheranimals studied. Congestion was associated with a 98% reduction in urineoutput rate (0.06 ml/min) and a >99% reduction in CrCl (1.0 ml/min).Treatment with negative pressure applied through the ureteral catheterswas associated with urine output and CrCl of 17% and 12%, respectively,of baseline values, and 9× and >10×, respectively, of congestion values.Levels of NGAL changed throughout the experiment, ranging from 68% ofbaseline during congestion to 258% of baseline after 90 minutes oftherapy. The final value was 130% of baseline. Levels of KIM-1 were 6times and 4 times of baseline for the first two 30-minute windows afterbaseline assessment, before increasing to 68×, 52×, and 63× of baselinevalues, respectively, for the last three collection periods. The 2-hourserum creatinine was 1.3 mg/dl. Histological examination revealed anoverall congestion level, measured by blood volume in capillary space,of 2.4%. Histological examination also noted several tubules withintraluminal hyaline casts and some degree of tubular epithelialdegeneration, a finding consistent with cellular damage.

Animal B: The animal weighed 50.2 kg and had a baseline urine outputrate of 2.62 ml/min and a measured CrCl of 172 ml/min (also higher thananticipated). Congestion was associated with an 80% reduction in urineoutput rate (0.5 ml/min) and an 83% reduction in CrCl (30 ml/min). At 50minutes into the congestion (20 minutes after the congestion baselineperiod), the animal experienced an abrupt drop in mean arterial pressureand respiration rate, followed by tachycardia. The anesthesiologistadministered a dose of phenylephrine (75 mg) to avert cardiogenic shock.Phenylephrine is indicated for intravenous administration when bloodpressure drops below safe levels during anesthesia. However, since theexperiment was testing the impact of congestion on renal physiology,administration of phenylephrine confounded the remainder of theexperiment.

Animal C: The animal weighed 39.8 kg and had a baseline urine outputrate of 0.47 ml/min, a baseline serum creatinine of 3.2 mg/dl, and ameasured CrCl of 5.4 ml/min. Congestion was associated with a 75%reduction in urine output (0.12 ml/min) and a 79% reduction in CrCl (1.6ml/min). It was determined that baseline NGAL levels were >5× the upperlimit of normal (ULN). Treatment with negative pressure applied to therenal pelvis through the ureteral catheters was associated with anormalization of urine output (101% of baseline) and a 341% improvementin CrCl (18.2 ml/min). Levels of NGAL changed throughout the experiment,ranging from 84% of baseline during congestion to 47% to 84% of baselinebetween 30 and 90 minutes. The final value was 115% of baseline. Levelsof KIM-1 decreased 40% from baseline within the first 30 minutes ofcongestion, before increasing to 8.7×, 6.7×, 6.6×, and 8× of baselinevalues, respectively, for the remaining 30-minute windows. Serumcreatinine level at 2 hours was 3.1 mg/dl. Histological examinationrevealed an overall congestion level, measured by blood volume incapillary space, of 0.9%. The tubules were noted to be histologicallynormal.

Animal D: The animal weighed 38.2 kg and had a baseline urine output of0.98 ml/min, a baseline serum creatinine of 1.0 mg/dl, and a measuredCrCl of 46.8 ml/min. Congestion was associated with a 75% reduction inurine output rate (0.24 ml/min) and a 65% reduction in CrCl (16.2ml/min). Continued congestion was associated with a 66% to 91% reductionof urine output and 89% to 71% reduction in CrCl. Levels of NGAL changedthroughout the experiment, ranging from 127% of baseline duringcongestion to a final value of 209% of baseline. Levels of KIM-1remained between 1× and 2× of baseline for the first two 30-minutewindows after baseline assessment, before increasing to 190×, 219×, and201× of baseline values for the last three 30-minute periods. The 2-hourserum creatinine level was 1.7 mg/dl. Histological examination revealedan overall congestion level 2.44× greater than that observed in tissuesamples for the treated animals (A, C) with an average capillary size2.33 times greater than that observed in either of the treated animals.The histological evaluation also noted several tubules with intraluminalhyaline casts as well as tubular epithelial degeneration, indicatingsubstantial cellular damage.

Summary

While not intending to be bound by theory, it is believed that thecollected data supports the hypothesis that venous congestion creates aphysiologically significant impact on renal function. In particular, itwas observed that elevation of the renal vein pressure reduced urineoutput by 75% to 98% within seconds. The association between elevationsin biomarkers of tubular injury and histological damage is consistentwith the degree of venous congestion generated, both in terms ofmagnitude and duration of the injury.

The data also appears to support the hypothesis that venous congestiondecreases the filtration gradients in the medullary nephrons by alteringthe interstitial pressures. The change appears to directly contribute tothe hypoxia and cellular injury within medullary nephrons. While thismodel does not mimic the clinical condition of AKI, it does provideinsight into the mechanical sustaining injury.

The data also appears to support the hypothesis that applying negativepressure to the renal pelvis through ureteral catheters can increaseurine output in a venous congestion model. In particular, negativepressure treatment was associated with increases in urine output andcreatinine clearance that would be clinically significant.Physiologically meaningful decreases in medullary capillary volume andsmaller elevations in biomarkers of tubular injury were also observed.Thus, it appears that by increasing urine output rate and decreasinginterstitial pressures in medullary nephrons, negative pressure therapymay directly decrease congestion. While not intending to be bound bytheory, by decreasing congestion, it may be concluded that negativepressure therapy reduces hypoxia and its downstream effects within thekidney in a venous congestion mediated AKI.

The experimental results appear to support the hypothesis that thedegree of congestion, both in terms of the magnitude of pressure andduration, is associated with the degree of cellular injury observed.Specifically, an association between the degree of urine outputreduction and the histological damage was observed. For example, treatedSwine A, which had a 98% reduction in urine output, experienced moredamage than treated Swine C, which had a 75% reduction in urine output.As would be expected, control Swine D, which was subjected to a 75%reduction in urine output without benefit of therapy for two and a halfhours, exhibited the most histological damage. These findings arebroadly consistent with human data demonstrating an increased risk forAKI onset with greater venous congestion. See e.g., Legrand, M. et al.,Association between systemic hemodynamics and septic acute kidney injuryin critically ill patients: a retrospective observational study.Critical Care 17:R278-86, 2013.

Example 3

Method

Inducement of negative pressure within the renal pelvis of farm swineusing ureteral catheters was performed for the purpose of evaluatingeffects of negative pressure therapy on hemodilution of the blood. Anobjective of these studies was to demonstrate whether a negativepressure delivered into the renal pelvis significantly increases urineoutput in a swine model of fluid resuscitation.

Two pigs were sedated and anesthetized using ketamine, midazolam,isoflurane and propofol. One animal (#6543) was treated with a ureteralcatheter and negative pressure therapy as described herein. The other,which received a Foley type bladder catheter, served as a control(#6566). Following placement of the ureretal catheters, the animals weretransferred to a sling and monitored for 24 hours.

Fluid overload was induced in both animals with a constant infusion ofsaline (125 mL/hour) during the 24 hour follow-up. Urine output volumewas measured at 15 minute increments for 24 hours. Blood and urinesamples were collected at 4 hour increments. As shown in FIG. 21, atherapy pump 818 was set to induce negative pressure within the renalpelvis 820, 821 (shown in FIG. 21) of both kidneys using a pressure of−45 mmHg (+/−2 mmHg).

Results

Both animals received 7 L of saline over the 24 hour period. The treatedanimal produced 4.22 L of urine while the control produced 2.11 L. Atthe end of 24 hours, the control had retained 4.94 L of the 7 Ladministered, while the treated animal retained 2.81 L of the 7 Ladministered. FIG. 26 illustrates the change in serum albumin. Thetreated animal had a 6% drop in the serum albumin concentration over 24hours, while the control animal had a 29% drop.

Summary

While not intending to be bound by theory, it is believed that thecollected data supports the hypothesis that fluid overload inducesclinically significant impact on renal function and, consequentlyinduces hemodilution. In particular, it was observed that administrationof large quantities of intravenous saline cannot be effectively removedby even healthy kidneys. The resulting fluid accumulation leads tohemodilution. The data also appears to support the hypothesis thatapplying negative pressure diuresis therapy using ureteral catheters tofluid overloaded animals can increase urine output, improve net fluidbalance and decrease the impact of fluid resuscitation on development ofhemodilution.

The preceding examples and embodiments of the invention have beendescribed with reference to various examples. Modifications andalterations will occur to others upon reading and understanding theforegoing examples. Accordingly, the foregoing examples are not to beconstrued as limiting the disclosure.

What is claimed is:
 1. A system for inducing negative pressure in a portion of a urinary tract of a patient, the system comprising: (a) a ureteral catheter comprising a distal portion configured for insertion within the patient's kidney and a proximal portion; (b) a bladder catheter comprising a distal portion configured for insertion within the patient's bladder and a proximal portion for application of negative pressure, the proximal portion configured to extend outside of the patient's body; and (c) a pump external to the patient's body for application of negative pressure through both the bladder catheter and the ureteral catheter, which in turn causes fluid from the kidney to be drawn into the ureteral catheter, through both the ureteral catheter and the bladder catheter, and then outside of the patient's body.
 2. The system according to claim 1, wherein the proximal portion of the ureteral catheter is in fluid communication with the distal portion of the bladder catheter.
 3. The system according to claim 1, wherein the distal portion of the ureteral catheter comprises a retention portion that comprises one or more protected drainage holes, ports or perforations and is configured to establish an outer periphery or protective surface area that inhibits mucosal tissue from occluding the one or more protected drainage holes, ports or perforations upon the application of negative pressure by the pump.
 4. The system according to claim 3, wherein the one or more protected drainage holes, ports or perforations are disposed on a protected surface area or inner surface area of the retention portion of the ureteral catheter, and wherein, upon application of negative pressure, the mucosal tissue conforms or collapses onto the outer periphery or protective surface area of the retention portion of the ureteral catheter and is thereby prevented or inhibited from occluding the one or more of the protected drainage holes, ports or perforations.
 5. The system according to claim 1, wherein the distal portion of the bladder catheter comprises a retention portion that comprises one or more protected drainage holes, ports or perforations and is configured to establish an outer periphery or protective surface area that inhibits mucosal tissue from occluding the one or more protected drainage holes, ports or perforations upon the application of negative pressure by the pump.
 6. The system according to claim 5, wherein the one or more protected drainage holes, ports or perforations are disposed on a protected surface area or inner surface area of the retention portion of the bladder catheter, and wherein, upon application of negative pressure, the mucosal tissue conforms or collapses onto the outer periphery or protective surface area of the retention portion of the bladder catheter and is thereby prevented or inhibited from occluding the one or more of the protected drainage holes, ports or perforations.
 7. The system according to claim 1, further comprising one or more physiological sensors configured to detect at least one physical parameter of the patient.
 8. The system according to claim 7, wherein the at least one physical parameter comprises one or more of volume of urine collected, urine composition, urine protein concentration, blood composition or blood flow.
 9. The system according to claim 8, wherein the at least one physical parameter of blood composition comprises one or more of hematocrit ratio, analyte concentration, protein concentration, or creatinine concentration.
 10. The system according to claim 8, wherein the at least one physical parameter of blood flow comprises one or more of blood pressure or blood flow velocity.
 11. The system according to claim 7, wherein the one or more physiological sensors comprise one or more of pulse oximetry sensor(s), blood pressure sensor(s), heart rate sensor(s), respiration sensor(s), capnography sensor(s), glucose sensor(s), blood velocity sensor(s), hemoglobin sensor(s), hematocrit sensor(s), protein sensor(s), creatinine sensor(s), analyte sensor(s), capacitance sensor(s), optical spectroscopy sensor(s) or combinations thereof.
 12. The system according to claim 1, wherein the pump provides an accuracy of about 10 mmHg or less.
 13. The system according to claim 1, wherein the negative pressure is provided within a range of about 2 mm Hg to about 150 mm Hg.
 14. A method for inducing negative pressure in a portion of a urinary tract of a patient, the method comprising: deploying a ureteral catheter into a ureter of a patient to maintain patency of fluid flow between a kidney and a bladder of the patient, the ureteral catheter comprising a distal portion for insertion within the patient's kidney and a proximal portion; deploying a bladder catheter into the bladder of the patient, wherein the bladder catheter comprises a distal portion for insertion within the patient's bladder and a proximal portion for application of negative pressure, the proximal portion extending outside of the patient's body; and applying negative pressure to the proximal end of the bladder catheter to induce negative pressure in a portion of the urinary tract of the patient to remove fluid from the patient.
 15. The method according to claim 14, wherein at least one of the ureteral catheter or the bladder catheter comprises (a) a proximal portion; and (b) a distal portion, the distal portion comprising a retention portion that comprises one or more protected drainage holes, ports or perforations and is configured to establish an outer periphery or protective surface area that inhibits mucosal tissue from occluding the one or more protected drainage holes, ports or perforations upon application of negative pressure through the catheter.
 16. The method according to claim 14, wherein the ureteral catheter is deployed and remains in the patient's body for at least 24 hours.
 17. The method according to claim 14, wherein the ureteral catheter is deployed and remains in the patient's body for at least 30 days or longer.
 18. The method according to claim 14, wherein the bladder catheter is replaced more often that the ureteral catheter.
 19. The method according to claim 14, wherein multiple bladder catheters are placed and removed during the indwell time for a single set of ureteral catheters. 